Colorado: Consolidated Chronology of State and County Boundaries

John H. Long, Editor; Peggy Tuck Sinko, Associate Editor; Robert Will, Historical Compiler; Douglas Knox, Book Digitizing Director; Emily Kelley, Research Associate and Digital Compiler; Laura Rico-Beck, GIS Specialist and Digital Compiler; Peter Siczewicz, ArcIMS Interactive Map Designer

Copyright The Newberry Library 2009

30 April 1803

The United States purchased Louisiana from France, taking formal possession on 20 December 1803; the boundaries were not clearly defined, but included the western half of the Mississippi drainage basin (from the Mississippi River to the Rocky Mountains). It included all of present Colorado east of the Rocky Mountains. (Parry, 57:27-40; Van Zandt, 23-26)

1 October 1804

The United States divided the Louisiana Purchase at the parallel of 33 degrees north latitude into the District of Louisiana and Orleans Territory. All of present Colorado east of the Rocky Mountains became part of the District of Louisiana; the District was not fully organized and was attached to Indiana Territory for administrative and judicial purposes. The District of Louisiana created the following counties from non-county area: CAPE GIRARDEAU District (Mo.) included parts of present Colorado, Kansas, and Missouri; NEW MADRID District (Mo.) included all or part of seven states, including part of present Colorado; STE. GENEVIEVE District (Mo.) included parts of present Colorado, Kansas, and Missouri; ST. LOUIS District (Mo.) included all or part of eight states, including part of present Colorado. (Terr. Papers U.S., 13: 51-52; U.S. Stat., vol. 2, ch. 38 [1804]/pp. 283-289)

Spain claimed the territory west of the Louisiana Purchase as part of Mexico; included that part of present Colorado west of the Rocky Mountains. (Paullin, 64-66, plates 94-95)

4 July 1805

CAPE GIRARDEAU (Mo.), NEW MADRID (Mo.), ST. LOUIS (Mo.), and STE. GENEVIEVE (Mo.) became districts (counties) in Louisiana Territory when the District of Louisiana was renamed Louisiana Territory. (U.S. Stat., vol. 2, ch. 31[1805]/pp. 331-332)

1 July 1806

NEW MADRID District (Mo.) gained from CAPE GIRARDEAU District (Mo.); areas within present Colorado were unchanged. (Terr. Papers U.S., 13:541-542)

15 August 1806

CAPE GIRARDEAU District (Mo.) gained from NEW MADRID District (Mo.), which was eliminated from present Colorado. (Ford, 5-6)

7 December 1812

All of present Colorado east of the Continental Divide became non-county area in Missouri Territory when Louisiana Territory was renamed Missouri Territory, and CAPE GIRARDEAU (Mo.), ST. LOUIS (Mo.), and STE. GENEVIEVE (Mo.) were eliminated from present Colorado. Map depicts non-county area of Missouri Territory in present Colorado. (Royce, 676-677, pls. 112, 144; Terr. Papers U.S., 14:599-601)

22 February 1819

The boundary between Missouri Territory and Spanish Mexico was altered when the Adams-Onis Treaty between the United States and Spain established the southern and western boundaries of the United States territory south of the parallel of 42 degrees north latitude. Map depicts non-county area of Missouri Territory in present Colorado. (Parry, 70:1-30; Van Zandt, 26-27)

10 August 1821

The state of Missouri was created from part of Missouri Territory; Missouri Territory was eliminated and all that part of the former Territory north and west of the state of Missouri, including part of present Colorado, became unorganized federal territory. (U.S. Stat., vol. 3, ch. 22[1820]/pp. 545-548 and res. 1[1821]/p. 645; Van Zandt, 117)

24 August 1821

Mexico gained its independence from Spain; that part of present Colorado that had been under the authority of Spain came under the control of the Republic of Mexico. ("Mexican War of Independence," New Handbook of Texas, 4:698)

2 March 1836

Texas declared its independence from Mexico. The Republic of Texas claimed part of present Colorado that had been within the Mexican Republic [not mapped]. ("Republic of Texas," New Handbook of Texas, 5:537-538; Swindler, 9:247, 249)

19 December 1836

BEXAR (Texas) boundaries were implicitly expanded to cover all non-county area in the Republic of Texas when the boundaries of the Texas Republic were defined. BEXAR included territory in present Colorado, Kansas, New Mexico, Oklahoma, Texas, and Wyoming. Map depicts only that part of BEXAR in present Colorado. Changes in BEXAR boundaries between December 1836 and March 1848 did not affect the area within present Colorado and are not mapped. (Texas Repub. Laws 1836, 1st cong./p. 133)

The Republic of Mexico lost territory to the Republic of Texas when the boundaries of the Texas Republic were defined; Mexico lost part of present Colorado. ("Mexican War of Independence," New Handbook of Texas, 4:698; Texas Repub. Laws 1836, 1st cong./p. 133)

29 December 1845

The United States Congress admitted Texas to the Union; state of Texas continued to claim part of present Colorado. (U.S. Stat., vol. 9, res. 1[1846]/p. 108)

15 March 1848

SANTA FE (Texas, extinct) created by the state of Texas from BEXAR (Texas); BEXAR eliminated from present Colorado. SANTA FE included territory in present Colorado, Kansas, New Mexico, Oklahoma, Texas, and Wyoming; only the portion in present Colorado is mapped here. SANTA FE boundaries changed on 31 December 1849, but the area within present Colorado was unchanged. (Texas Laws 1847, 2d reg. sess., ch. 87/p. 95)

4 July 1848

Treaty of Guadalupe Hidalgo ended the Mexican War between the United States and Mexico. Mexico recognized the United States' annexation of Texas and agreed that the Rio Grande River, not the Nueces River, was the true boundary between Mexico and Texas. That part of the former Republic of Mexico in present Colorado became unorganized federal territory. ("Treaty of Guadalupe Hidalgo," New Handbook of Texas, 6:558-559; Parry, 102: 29-59; U.S. Stat., vol. 9[1848]/pp. 922-943)

2 July 1849

The state of Deseret was proposed by Mormon leaders, and the General Assembly met on 2 July 1849. The large state was to include parts of present Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah, and Wyoming, but this proposal never gained widespread support in the U.S. Congress. Utah Territory, created on 9 September 1850, was not as extensive, but covered much of the area of the state of Deseret, including the Great Basin. Only the portion of Deseret in present Colorado is mapped here. (Atlas of Utah, 160-161; Brown, Cannon, and Jackson, 90-91)

9 September 1850

The United States created Utah Territory from unorganized federal territory and part of the state of Texas; included all of present Colorado west of the Rocky Mountains. All that part of Deseret in present Colorado was included in Utah Territory. Part of SANTA FE (Texas, extinct) in present Colorado was included in the area organized as Utah Territory on this date, although the purchase of the area by the United States was not officially approved until 13 December 1850; the remainder of SANTA FE was added to unorganized federal territory. SANTA FE effectively eliminated from present Colorado. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452 and ch. 51[1850]/pp. 453-458; Van Zandt, 159)

13 December 1850

The United States created New Mexico Territory from unorganized federal territory and land sold to the United States by the state of Texas; New Mexico Territory included parts of present Colorado, Arizona, Nevada, and New Mexico. Map depicts that part of New Mexico Territory in present Colorado. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452; Van Zandt, 160-162)

9 January 1852

TAOS (New Mexico) created by New Mexico Territory from non-county area; included parts of present Colorado, Arizona, Nevada, and New Mexico. The non-county area in that part of Colorado included in New Mexico Territory was eliminated. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

3 March 1852

Utah Territory created new counties and redefined the boundaries of other counties, eliminating all non-county area in that part of present Colorado included in Utah Territory:

13 January 1854

GREEN RIVER (Utah Territory, extinct) gained from GREAT SALT LAKE (now SALT LAKE, Utah), SANPETE (Utah), and UTAH (Utah); lost to DAVIS (Utah) and lost to creation of SUMMIT (Utah). GREAT SALT LAKE also lost to creation of SUMMIT (Utah). GREAT SALT LAKE and UTAH eliminated from present Colorado. (Utah Terr. Laws 1853, 3d sess./pp. 14-15)

17 January 1854

IRON (Utah) lost to creation of CARSON (Utah Territory, extinct); area within present Colorado was unchanged. (Utah Terr. Laws 1853, 3d sess./p. 19)

30 May 1854

The United States created Kansas Territory from unorganized federal territory; included all of present Kansas and part of present Colorado. Map depicts that part of Kansas Territory in present Colorado. (Van Zandt, 138-139)

The United States created Nebraska Territory from unorganized federal territory; included all of present Nebraska, and parts of present Colorado, North Dakota, South Dakota, Montana, and Wyoming. Map depicts that part of Nebraska Territory in present Colorado. (U.S. Stat., vol. 10, p. 277; Van Zandt, 136-137)

15 June 1854

GREEN RIVER (Utah Territory, extinct) fully organized, detached from GREAT SALT LAKE (now SALT LAKE, Utah). (Gowans and Campbell, 63)

18 January 1855

SANPETE (Utah) exchanged with JUAB (Utah); area within present Colorado was unchanged. (Utah Terr. Laws 1854, 4th sess., ch. 81/pp. 276-277)

25 August 1855

ARAPAHOE (Kansas Territory, extinct) created by Kansas Territory from non-county area; ARAPAHOE was located entirely within present Colorado. ARAPAHOE not fully organized, attached to MARSHALL (Kansas) "for all business purposes." (Kans. Terr. Laws 1855, 1st leg., chs. 37-38/pp. 217-218)

WASHINGTON (Kansas) created by Kansas Territory from non-county area; included parts of present Kansas and Colorado. WASHINGTON not fully organized, attached to ALLEN (Kansas) "for judicial and other purposes." (Kans. Terr. Laws 1855, 1st leg., ch. 33/pp. 214-215)

5 January 1856

BEAVER (Utah) created by Utah Territory from IRON (Utah); BEAVER included parts of present Colorado, Utah, and Nevada. (Utah Terr. Laws 1855, 5th sess., sec. 9/p. 7)

WASHINGTON (Utah) gained from IRON (Utah) all along its northern line when the boundary was shifted slightly from 30 degrees, 30 minutes north latitude to four miles north of Fort Harmony. (Utah Terr. Laws 1855, 5th sess., sec. 10/p. 7)

23 February 1856

WASHINGTON (Utah) fully organized, detached from IRON (Utah). (Larson, Andrew, 26)

20 February 1857

WASHINGTON (Kansas) lost to non-county area in Kansas Territory; WASHINGTON eliminated from present Colorado. (Kans. Terr. Laws 1857, 2d leg., sec. 33/p. 45)

22 December 1857

GREEN RIVER (Utah Territory, extinct) was disorganized and attached to GREAT SALT LAKE (now SALT LAKE, Utah) "for election, revenue and judicial purposes" because most settlers had left the area. (Utah Terr. Laws 1857, 7th sess./p. 1)

21 September 1858

Kansas Territorial Governor, James Denver, issued commissions for county officials for ARAPAHOE (Kansas Territory, extinct). There is disagreement as to whether the county was ever officially organized. (Bancroft, 402; Fritz, 185-186; "Governor Denver's Admin.," 5:512; Kansas Counties, KSHS, http://www.kshs.org/genealogists/places/counties.htm, 2 March 2005; Wynkoop, 13:71-72)

17 January 1859

GREEN RIVER (Utah Territory, extinct) was reorganized, detached from GREAT SALT LAKE (now SALT LAKE, Utah). (Utah Terr. Laws 1858, 8th sess., ch. 11/pp. 19-20)

1 March 1859

BRODERICK (Kansas Territory, extinct), EL PASO (Kansas Territory, extinct), FREMONT (Kansas Territory, extinct), MONTANA (Kansas Territory, extinct), and ORO (Kansas Territory, extinct) all created by Kansas Territory from ARAPAHOE (Kansas Territory, extinct). These counties were located entirely within present Colorado. Act passed 7 February 1859, took effect 1 March 1859. Counties were not fully organized. (Kans. Terr. Laws 1859, 5th leg., ch. 44/pp. 357-359; Bancroft, 402)

24 October 1859

Voters approved creation of the Territory of Jefferson and authorized formation of a provisional government. The first session of the Jefferson Territorial Legislature met 7 November 1859 in Denver City. This extralegal territory was not recognized by the United States. The Territory of Jefferson included all of present Colorado and parts of present Nebraska, Wyoming, and Utah. (Smiley, 305-318)

28 November 1859

The extralegal Territory of Jefferson created 12 counties:

1 February 1860

MORA (New Mexico) created by New Mexico Territory from TAOS (New Mexico); MORA included parts of present Colorado and New Mexico. (N.M. Terr. Laws 1859-1860, 9th assy. /p. 76)

21 February 1860

PEKETON (Kansas, extinct) created by Kansas Territory from non-county area; PEKETON included territory in present Colorado and Kansas. (Kans. Terr. Laws 1860, ch. 42/p. 83 and ch. 78, sec. 4/p. 133)

12 January 1861

TAOS (New Mexico) lost to creation of SAN JUAN (New Mexico Territory, original, extinct); area within present Colorado was unchanged. (N.M. Terr. Laws 1860-1861, 10th assy./p. 16)

18 January 1861

BEAVER (Utah), IRON (Utah), and WASHINGTON (Utah) all lost to HUMBOLDT (Utah Territory, extinct) and ST. MARY'S (Utah Territory, extinct); areas within present Colorado were unchanged. (Utah Terr. Laws 1860, 10th sess./p. 19)

29 January 1861

ARAPAHOE (Kansas Territory), BRODERICK (Kansas Territory), EL PASO (Kansas Territory), FREMONT (Kansas Territory), MONTANA (Kansas Territory), and ORO (Kansas Territory) all eliminated when the state of Kansas was admitted to the Union. PEKETON (Kansas, extinct) lost territory when the state of Kansas was admitted to the Union; PEKETON eliminated from present Colorado. The area within the bounds of present Colorado that had been part of Kansas Territory temporarily reverted to unorganized federal territory until the official creation of Colorado Territory on 28 February 1861. (U.S. Stat., vol. 12, ch. 20 [1861]/pp. 126-128; Van Zandt, 138-139)

28 February 1861

The United States created Colorado Territory from Nebraska, New Mexico, and Utah Territories, and from the former Kansas Territory. MORA (New Mexico), TAOS (New Mexico), BEAVER (Utah), GREEN RIVER (Utah Territory, extinct), IRON (Utah), SANPETE (Utah), and WASHINGTON (Utah) all lost to Colorado Territory and were eliminated from present Colorado. (U.S. Stat., vol. 12, ch. 59[1861]/pp. 172-177; Van Zandt, 141)

6 June 1861

Robert W. Steele, Provisional Governor of the Territory of Jefferson, declared the Territory disbanded upon the arrival of William Gilpin, the new territorial governor of Colorado. All Jefferson Territory counties were eliminated: ARRAPPAHOE, CHEYENNE, EL PASO, FOUNTAIN, HEELE, JACKSON, JEFFERSON, MOUNTAIN, NORTH, PARK, SARATOGA, and ST. VRAIN. (Smiley, 321-322)

1 November 1861

Colorado Territory created 17 counties. (Colo. Terr. Laws 1861, 1st sess.; for sections on particular counties. see following citations):

The Cheyenne Indian Reserve became a non-county area in Colorado Territory. All remaining non-county area eliminated. (Colo. Terr. Laws 1861, 1st sess., pp. 53-57; Royce, 824-825, 838-839, pl. cxvi)

7 November 1861

GUADALOUPE renamed CONEJOS. (Colo. Terr. Laws 1861, 1st sess., p. 143)

24 February 1864

CONEJOS gained from COSTILLA. (Colo. Terr. Laws 1864, 3d sess., pp. 68-69)

11 March 1864

FREMONT gained from PUEBLO. (Colo. Terr. Laws 1864, 3d sess., pp. 69-70)

10 February 1865

CONEJOS attached to COSTILLA "for judicial purposes." (Colo. Terr. Laws 1865, 4th sess., sec. 18/p. 53)

DOUGLAS and WELD attached to ARAPAHOE "for judicial purposes." (Colo. Terr. Laws 1865, 4th sess., sec. 15/p. 53)

6 February 1866

FREMONT gained from EL PASO and PUEBLO. (Colo. Terr. Laws 1866, 5th sess., pp. 47-48)

9 February 1866

LAS ANIMAS created by Colorado Territory from HUERFANO. (Colo. Terr. Laws 1866, 5th sess., pp. 49-50)

29 December 1866

SAGUACHE created by Colorado Territory from COSTILLA; SAGUACHE not fully organized, attached to COSTILLA "for judicial purposes." (Colo. Terr. Laws 1866, 6th sess., p. 54)

11 January 1867

DOUGLAS and WELD fully organized, both detached from ARAPAHOE. LARIMER detached from BOULDER, attached to WELD "for judicial purposes." Attachment of SAGUACHE to COSTILLA "for judicial purposes" was confirmed. (Colo. Terr. Laws 1866, 6th sess., pp. 60-61)

18 June 1867

SAGUACHE fully organized, detached from COSTILLA. (Hall, 4:304)

6 January 1868

LAKE gained from FREMONT. (Colo. Terr. Laws 1867, 7th sess., ch. 20, sec. 45/p. 163)

9 January 1868

COSTILLA gained small area from LAS ANIMAS, lost small area to HUERFANO. HUERFANO gained from COSTILLA and FREMONT, exchanged with LAS ANIMAS, lost to PUEBLO. A remnant of HUERFANO east of the Cheyenne Indian Reserve became Non-County Area 1. The former northwest corner of HUERFANO became Non-County Area 2. PUEBLO gained from FREMONT, and HUERFANO, and gained part of the Cheyenne Indian Reserve. (Colo. Terr. Laws 1867, 7th sess., ch. 20, p. 164)

11 February 1870

BENT created by Colorado Territory from LAS ANIMAS and PUEBLO. (Colo. Terr. Laws 1870, 8th sess., sec. 3/pp. 16-17; sec. 2/p. 24)

EL PASO gained from Cheyenne Indian Reserve. (Colo. Terr. Laws 1870, 8th sess., sec. 5/p. 17)

GREENWOOD (extinct) created by Colorado Territory from PUEBLO, part of the Cheyenne Indian Reserve, and all of Non-County Area 1 (remnant of HUERFANO). (Colo. Terr. Laws 1870, 8th sess., sec. 1/p. 16)

1870

In 1870, CONEJOS was fully organized, detached from COSTILLA. (HRS Colo., Conejos, 41)

9 February 1872

Legislature authorized creation of PLATTE (proposed) from WELD, subject to voter approval. Act repealed 9 February 1874; creation did not take effect. (Colo. Terr. Laws 1872, 9th sess., pp. 80-81; Colo. Terr. Laws 1874, 10th sess., p. 82)

SAGUACHE gained from LAKE. (Colo. Terr. Laws 1872, 9th sess., pp. 81-82)

2 February 1874

ELBERT created by Colorado Territory from DOUGLAS, GREENWOOD (extinct), and Cheyenne Indian Reserve. (Colo. Terr. Laws 1874, 10th sess., pp. 69-70)

GRAND created by Colorado Territory from SUMMIT; GRAND not fully organized, attached to CLEAR CREEK "for legislative, legal, and judicial purposes." GRAND's boundary with LARIMER (described as the "summit of the Snowy Range") was open to different interpretations and both counties claimed the area known as North Park [see also 1 November 1861]. In 1886, the Colorado Supreme Court ruled that the boundary ran on the Continental Divide, and the GRAND boundary is mapped here in accordance with that court ruling. (Colo. Terr. Laws 1874, 10th sess., pp. 70-71; "Grand County v. Larimer County," in Colo. Rpts., 9:268-281; Royce, 848-849, pl. cxvi)

6 February 1874

BENT gained all of GREENWOOD (extinct); GREENWOOD eliminated. (Colo. Terr. Laws 1874, 10th sess., pp. 61-62)

9 February 1874

Act of 9 February 1872, authorizing creation of PLATTE (proposed) from WELD, was repealed. (Colo. Terr. Laws 1874, 10th sess., p. 82)

10 February 1874

COSTILLA gained from SAGUACHE. (Colo. Terr. Laws 1874, 10th sess., secs. 1, 13/pp. 66, 68)

HINSDALE created by Colorado Territory from CONEJOS and LAKE. (Colo. Terr. Laws 1874, 10th sess., sec. 2/p. 66)

LA PLATA created by Colorado Territory from CONEJOS and LAKE. (Colo. Terr. Laws 1874, 10th sess., sec. 3/p. 67)

RIO GRANDE created by Colorado Territory from CONEJOS and COSTILLA. (Colo. Terr. Laws 1874, 10th sess., sec. 1/p. 66)

8 September 1874

GRAND fully organized, detached from CLEAR CREEK. (Black, 101-103)

1 May 1876

SAN JUAN created by Colorado Territory from HINSDALE and LA PLATA. HINSDALE gained from LA PLATA. Act passed 31 January 1876; took effect 1 May 1876. (Colo. Terr. Laws 1876, 11th sess., secs. 1, 9, 12/pp. 58-61)

1 August 1876

The state of Colorado was created from Colorado Territory and admitted to the Union. (Van Zandt, 141; U.S. Stat., vol. 18, part 3 [1876], p. 474)

18 January 1877

OURAY created from SAN JUAN. (Colo. Laws 1876, 1st sess., ch. 21, par. 385-392/pp. 207-209)

29 January 1877

ROUTT created from GRAND. The boundary between ROUTT and GRAND was open to different interpretations and is mapped here in accordance with a District Court decision of 21 July 1891. (Colo. Laws 1876, 1st sess., ch. 21, par. 393-400/pp. 209-211); "Grand County v. Larimer County," in Colo. Rpts., 9:268-281; "Routt County v. Grand County," in Pacific Reporter, 35: 1061-1064; Black, 113)

9 March 1877

CUSTER created from FREMONT and all of Non-County Area 2; Non-County Area 2 eliminated. (Colo. Laws 1876, 1st sess., ch. 21, par. 401-410/pp. 211-213)

GUNNISON created from LAKE; GUNNISON not fully organized, attached to LAKE "for senatorial, representative and judicial purposes." (Colo. Laws 1876, 1st sess., ch. 21, par. 411, 418/pp. 213-216)

22 May 1877

GUNNISON fully organized, detached from LAKE. (Hall, 4:147)

8 February 1879

CARBONATE (extinct) created from LAKE and small areas of SUMMIT; see 10 February 1879. SUMMIT gained small areas from LAKE along the Continental Divide. (Colo. Laws 1879, 2d sess., pp. 45-47)

10 February 1879

CHAFFEE created from LAKE; CHAFFEE included all of LAKE that remained following the creation of CARBONATE (extinct) on 8 February 1879. CARBONATE was renamed LAKE. In effect, LAKE regained all the territory it lost two days earlier when CARBONATE (extinct) was created, and lost all of the territory that became CHAFFEE; CARBONATE eliminated. (Colo. Laws 1879, 2nd sess., p. 48)

12 February 1879

RIO GRANDE exchanged with SAGUACHE. (Colo. Laws 1879, 2d sess., p. 48)

19 February 1881

DOLORES created from OURAY. (Colo. Laws 1881, 3d sess., pp. 92-96)

23 February 1881

PITKIN created from GUNNISON. (Colo. Laws 1881, 3d sess., pp. 89-92)

10 February 1883

GARFIELD created from SUMMIT. (Colo. Laws 1883, 4th sess., pp. 130-133)

11 February 1883

DELTA created from GUNNISON. (Colo. Laws 1883, 4th sess., pp. 124-127)

EAGLE created from SUMMIT. (Colo. Laws 1883, 4th sess., pp. 127-130)

MONTROSE created from GUNNISON. (Colo. Laws 1883, 4th sess., pp. 136-139)

14 February 1883

MESA created from GUNNISON. (Colo. Laws 1883, 4th sess., pp. 133-136)

27 February 1883

UNCOMPAHGRE (extinct) created from GUNNISON, MONTROSE, and OURAY; OURAY regained all of UNCOMPAHGRE when it was renamed OURAY and eliminated three days later on 2 March 1883. MONTROSE gained from GUNNISON. (Colo. Laws 1883, 4th sess., pp. 139-142)

2 March 1883

SAN MIGUEL created when OURAY was renamed SAN MIGUEL, and UNCOMPAHGRE (extinct) was renamed OURAY; UNCOMPAHGRE eliminated. OURAY in effect regained the area it lost three days earlier to the creation of UNCOMPAHGRE and lost all the territory that became SAN MIGUEL. (Colo. Laws 1883, 4th sess., sec. 1/p. 123)

14 April 1885

ARCHULETA created from CONEJOS. (Colo. Laws 1885, 5th sess., pp. 40-42)

April 1886

During the April 1886 term, the Colorado Supreme Court ruled on the boundary between GRAND and LARIMER. The decision, in favor of LARIMER, stated that the "snowy range," referenced in the 1861 law creating LARIMER, referred to the Continental Divide, not the Medicine Bow Mountains, located to the east. ("Grand County v. Larimer County," in Colo. Rpts., 9:268-281)

9 February 1887

WASHINGTON created from WELD. (Colo. Laws 1887, 6th sess., pp. 251-254)

25 February 1887

LOGAN created from WELD. (Colo. Laws 1887, 6th sess., pp. 247-250)

19 February 1889

MORGAN created from WELD. (Colo. Laws 1889, 7th sess., S.B. 40, pp. 267-270)

15 March 1889

YUMA created from WASHINGTON. (Colo. Laws 1889, 7th sess., H.B. 90, pp. 476-479)

25 March 1889

CHEYENNE created from BENT and ELBERT. (Colo. Laws 1889, 7th sess., S.B. 116, pp. 56-59)

OTERO created from BENT. (Colo. Laws 1889, 7th sess., S.B. 31, pp. 281-284)

RIO BLANCO created from GARFIELD. (Colo. Laws 1889, 7th sess., H.B. 107, pp. 325-328)

27 March 1889

PHILLIPS created from LOGAN. (Colo. Laws 1889, 7th sess., H.B. 127, pp. 288-292)

9 April 1889

SEDGWICK created from LOGAN. (Colo. Laws 1889, 7th sess., H.B. 148, pp. 340-343)

11 April 1889

KIOWA created from BENT. (Colo. Laws 1889, 7th sess., H.B. 337, pp. 222-225)

KIT CARSON created from ELBERT. (Colo. Laws 1889, 7th sess. S.B. 48, pp. 225-228)

LINCOLN created from ELBERT and BENT. (Colo. Laws 1889, 7th sess., S.B. 106, pp. 234-237)

PROWERS created from BENT. (Colo. Laws 1889, 7th sess., S.B. 35, pp. 294-297)

16 April 1889

BACA created from LAS ANIMAS. (Colo. Laws 1889, 7th sess., S.B. 37, pp. 26-28)

MONTEZUMA created from LA PLATA. (Colo. Laws 1889, 7th sess., H.B. 220, pp. 262-265)

20 April 1889

JEFFERSON boundaries were clarified [no change]. (Colo. Laws 1889, 7th sess., H.B. 256, pp. 100-101)

27 March 1893

MINERAL created from HINSDALE, RIO GRANDE, and SAGUACHE; mistake in description corrected 24 April 1895. (Colo. Laws 1893, 9th sess., ch. 52, pp. 94-97; Colo. Laws 1895, 10th sess., ch. 92, pp. 205-206)

24 April 1895

MINERAL boundaries clarified to correct mistake of 27 March 1893 [no change]. (Colo. Laws 1895, 10th sess., ch. 92, pp. 205-206)

23 March 1899

TELLER created from EL PASO and FREMONT. (Colo. Laws 1899, 12th sess., ch. 144, pp. 359-365)

15 November 1902

ADAMS created from ARAPAHOE; ARAPAHOE was renamed SOUTH ARAPAHOE. Act passed 15 April 1901; took effect 15 November 1902 following adoption of article XX of the Colorado Constitution in the November 1902 election. (Colo. Laws 1901, 13th sess., chs. 57-58, pp. 133-143)

City and County of DENVER created from SOUTH ARAPAHOE (now ARAPAHOE) following the approval of Colorado Constitutional Amendment XX by voters on 4 November 1902. The governor issued his official proclamation 1 December 1902. (Colo. Laws 1901, 13th sess., ch. 46, pp. 97-106 and ch. 68, pp. 162-165; King, 225-233; "Denver vs. Adams County," in Colo. Rpts., 33:1)

11 April 1903

SOUTH ARAPAHOE renamed ARAPAHOE. (Colo. Laws 1903, 14th sess., ch. 80, sec. 1/pp. 164-165)

12 May 1903

WASHINGTON gained from ADAMS. (Colo. Laws 1903, 14th sess., ch. 81, pp. 169-172; Colo. Laws 1901, 13th sess., ch. 57, sec. 14/p. 137)

YUMA gained from ADAMS. (Colo. Laws 1903, 14th sess., ch. 82, pp. 173-176; Colo. Laws 1901, 13th sess., ch. 57, sec. 14/p. 137)

20 April 1905

ARCHULETA exchanged with CONEJOS. (Colo. Laws 1905, 15th sess., ch. 74, pp. 153-154)

9 April 1907

Legislature authorized PITKIN to gain from GUNNISON, dependent on local referendum; change did not take effect. (Colo. Laws 1907, 16th sess., ch. 143, pp. 317-318)

PARK gained from JEFFERSON. (Colo. Laws 1907, 16th sess., ch. 142, p. 316)

5 May 1909

JACKSON created from LARIMER. (Colo. Laws 1909, 17th sess., ch. 179, pp. 432-436)

27 February 1911

MOFFAT created from ROUTT. (Colo. Laws 1911, 18th sess., ch. 173, pp. 516-521)

29 May 1911

CROWLEY created from OTERO. (Colo. Laws 1911, 18th sess., ch. 111, pp. 277-282)

8 March 1913

ALAMOSA created from CONEJOS and COSTILLA.; CONEJOS gained small area from COSTILLA. (Colo. Laws 1913, 19th sess., ch. 6, pp. 19-24)

24 March 1913

MONTROSE exchanged with OURAY when the boundary was placed on public land survey lines. (Colo. Laws 1913, 19th sess., ch. 46, pp. 140-141)

8 May 1913

Boundary between GILPIN and JEFFERSON was clarified [no change]. (Colo. Laws 1913, 19th sess., ch. 86/p. 284)

17 April 1917

OURAY exchanged with SAN MIGUEL when part of the boundary was placed on public land survey lines. Mistake in description corrected 16 March 1984. (Colo. Laws 1917, 21st sess., ch. 38, pp. 118-119)

2 March 1923

DOLORES exchanged with SAN MIGUEL; mistake in description corrected 9 April 1927. (Colo. Laws 1923, 24th sess., ch. 90, pp. 245-246)

9 April 1927

Boundary between DOLORES and SAN MIGUEL was redefined to correct mistake of 2 March 1923 [no change]. (Colo. Laws 1927, 26th sess., ch. 82, pp. 278-279)

by 1930

ROUTT gained from GARFIELD and RIO BLANCO when the boundary was shifted to public land survey lines. (USGS, Glenwood Springs Quad., 1930)

11 December 1941

DENVER gained from ADAMS; 1st Airport Addition, 26th Ave. & Yosemite St. (City & County Map; Annexation Map)

30 November 1942

DENVER gained from ADAMS; 2nd Airport Addition, 32nd Ave. & Havana St. (City & County Map; Annexation Map)

31 December 1943

DENVER gained from ARAPAHOE; Mountain View Park, Alameda Ave. & Federal Blvd. (City & County Map; Annexation Map)

27 November 1944

DENVER gained from ARAPAHOE; University Hills #1, Yale Ave. & Colorado Blvd. (City & County Map; Annexation Map)

21 December 1944

DENVER gained from ARAPAHOE; Davis Ranch, Jewell Ave. & Pecos St. (City & County Map; Annexation Map)

31 December 1945

DENVER gained from ARAPAHOE; Kirkland #1, Yale Ave. & Steele St. (City & County Map; Annexation Map)

31 December 1946

DENVER gained from ARAPAHOE: Mar Lee, Sheridan Blvd. and Mexico Ave.; University Hills #2, Yale Ave. & Dahlia St.; Brentwood, Federal Blvd. & Jewell St. (City & County Map; Annexation Map)

13 February 1947

ARAPAHOE gained small area from DENVER by court order; Myrtle Hill Subdivision, part of sec. 31, Township 4 South, Range 67 West. (Arapahoe Co. Action #6556, Book 575, p. 229; City & County Map; Annexation Map)

27 March 1947

DENVER gained from ARAPAHOE; Westwood, Federal Blvd. & Alameda Ave. (City & County Map; Annexation Map)

27 December 1947

DENVER gained small area from ARAPAHOE; Kirkland #2, Yale Ave. & High St. (City & County Map; Annexation Map)

31 December 1947

DENVER gained from ARAPAHOE; The Island, Federal Blvd. & Mississippi Ave. (City & County Map; Annexation Map)

18 March 1948

DENVER gained from JEFFERSON; Inspiration Point, 48th Ave. & Sheridan Blvd. (Annexation Map)

3 April 1948

DENVER gained small area from ARAPAHOE; Kimball Kroft-Block 2, Yale Ave. & Franklin St. (Annexation Map)

5 October 1948

DENVER gained small area from ARAPAHOE; Correction No. 1, Colorado Blvd. & Dartmouth Ave. (Annexation Map)

9 April 1949

DENVER gained from ADAMS [Jett & Stillman, 52nd Ave. & Platte River] and gained from ARAPAHOE [Kimball Kroft-Block 1 2nd Filing, Yale Ave. & Humboldt St.; Sheridan Terrace, Sheridan Blvd. & Alameda Ave.; Kimball Kroft, Yale Ave. & Downing St.]. (Annexation Map)

11 April 1949

DENVER gained small area from ARAPAHOE; Correction No. 2, Federal Blvd. & Kentucky Ave. (Annexation Map)

16 February 1950

DENVER gained from ADAMS; C.B. & Q. Industrial, Colorado Blvd. & 52nd St. (Annexation Map)

15 August 1950

DENVER gained from ARAPAHOE; Wellshire Hills #1, Yale Ave. & Steele St.; Wellshire Golf Course, Colorado Blvd. & Hampden Ave. (Annexation Map)

11 December 1950

DENVER gained from ARAPAHOE; Fairhills, Federal Blvd. & Yale Ave. (Annexation Map)

20 February 1951

DENVER gained from ARAPAHOE; Sunset Terrace, Colorado Blvd. & C&S Tracts. (Annexation Map)

18 July 1951

DENVER gained from ARAPAHOE: University Hills #3, Holly St. & Hampden Ave.; Monaco Gardens, Alameda Ave. & Monaco Blvd. (Annexation Map)

29 October 1951

DENVER gained from ADAMS; 3rd Airport Addition, Havana St. & 26th Ave. (Annexation Map)

7 January 1952

DENVER gained from ARAPAHOE; Wellshire Hills #2, Steele St. & Bates Ave. (Annexation Map)

16 July 1952

DENVER gained from ARAPAHOE; Wellshire Hills #3, Steele St. & Dartmouth Ave. (Annexation Map)

2 September 1952

DENVER gained from ARAPAHOE; Wellshire Hills #4, Steele St. & Bates Ave. (Annexation Map)

2 April 1953

DENVER gained from ADAMS; 4th Airport Addition, Yosemite St. & Montview Blvd. (Annexation Map)

2 October 1953

DENVER gained from ADAMS [5th Airport Addition, Lima St. & 26th Ave.] and gained from ARAPAHOE [Plaza Terrace #1, Mexico Ave. & Dahlia St.]. (Annexation Map)

16 March 1954

DENVER gained from ARAPAHOE: Plaza Terrace #2, Mexico Ave. & Dahlia St.; Harvey Park, Jewell Ave. & Sheridan Blvd. (Annexation Map)

28 April 1954

DENVER gained from ARAPAHOE: University Hills #4, Yale Ave. & Bellaire St.; University Hills #5, Colorado Blvd. & Amherst Ave. (Annexation Map)

23 August 1954

DENVER gained from ARAPAHOE; Virginia Village, Colorado Blvd. & Arizona Ave. (Annexation Map)

8 November 1954

DENVER gained from ARAPAHOE; Cherry Creek #1, Exposition Ave. & Cherry Creek. (Annexation Map)

7 December 1954

DENVER gained from ARAPAHOE; Grace Methodist Church, Yale Ave. & Elm St. (Annexation Map)

4 January 1955

DENVER gained from ARAPAHOE; Plaza Heights #1, Yale Ave. & Dahlia St. (Annexation Map)

31 January 1955

DENVER gained from ARAPAHOE; Cherry Creek #2, Quebec St. & Cherry Creek. (Annexation Map)

15 February 1955

DENVER gained from ARAPAHOE; Bear Creek, Sheridan Blvd. & Bear Creek. (Annexation Map)

5 April 1955

DENVER gained from ARAPAHOE; Winston Downs, Alameda Ave. & Monaco St. (Annexation Map)

15 April 1955

DENVER gained from ARAPAHOE; Cherry Creek #3, Roslyn St. & Cherry Creek. (Annexation Map)

1 June 1955

DENVER gained from ARAPAHOE; Happy Canyon #1, Hampden Ave. & Holly St. (Annexation Map)

30 June 1955

DENVER gained from ARAPAHOE: City Park Dairy, [Dahlia St. & Cherry Creek]; Hutchinsons University Place [Colorado Blvd. & Wesley Ave.]; Panorama Park [Holly St. & Jewell Ave.]. (Annexation Map)

13 September 1955

DENVER gained from ARAPAHOE; Happy Canyon #2, Holly St. & Mansfield Ave. (Annexation Map; Denver Ord. 284-55, Engr. File 638, Engr. Plat Book 38/28)

14 September 1955

ARAPAHOE gained 1.8 acres from DENVER by court ordered de-annexation: Kirkland 1st Addition, Cornell Ave. & University Blvd. (Annexation Map)

18 October 1955

DENVER gained from ARAPAHOE; Plaza Heights #2, Vassar Ave. & Dahlia St. (Annexation Map)

4 January 1956

DENVER gained from ARAPAHOE; Denver Public School No. 1, Virginia Ave. & Oneida St. (Annexation Map)

10 May 1956

DENVER gained from ARAPAHOE; Hamilton Watch Co., Jewell Ave. & Kearney St. (Annexation Map)

14 May 1956

DENVER gained from ARAPAHOE; Platte River, Yale Ave. & Platte River. (Annexation Map)

28 September 1956

DENVER gained from ARAPAHOE: Wall School, Monaco St. Pkwy. & Virginia Ave.; Happy Canyon School, Mansfield Ave. & Holly St. (Annexation Map)

7 January 1958

DENVER gained from ARAPAHOE; Loretto Heights College, Amherst Ave. & Federal Blvd. (Annexation Map)

26 February 1958

DENVER gained from ARAPAHOE; St. Andrew Avellino Seminary, Birch St. & Mississippi Ave. (Annexation Map)

15 April 1958

DENVER gained from ARAPAHOE: City Wolff, Jewell Ave. & Leyden St.; Ashgrove School, Mexico Ave. & Ivy St. (Annexation Map)

5 August 1958

DENVER gained from ARAPAHOE: Glendale Area No. 1, Tennessee Ave. & Dahlia St.; Glendale Area No. 2, Kentucky Ave. & Dexter St. (Annexation Map)

2 September 1958

DENVER gained 1.3 acres from ARAPAHOE; Glendale Area No. 3, Colorado Blvd. & Mississippi Ave. (Annexation Map; Denver Ord. 303-58, Engr. File 706, Engr. Plat Book 40/39)

7 October 1958

DENVER gained from ARAPAHOE; Arapahoe County, Colorado Blvd. & Warren Ave. (Annexation Map; Denver Ord. 333-58, Engr. File 708, Engr. Plat Book 40/41)

16 December 1958

DENVER gained from ARAPAHOE; Glendale Area No. 4, Kentucky Ave. & Dexter St. (Annexation Map)

6 January 1959

DENVER gained from ARAPAHOE; Glendale Area No. 5, Exposition Ave. & Cherry Creek. (Annexation Map)

4 February 1959

DENVER gained from ARAPAHOE; Glendale Area No. 6, Kentucky Ave. & Dexter St. (Annexation Map)

15 April 1959

DENVER gained from ARAPAHOE; Hillel Academy, Hudson St. & Dakota Ave. (Annexation Map)

2 June 1959

DENVER gained from ARAPAHOE; Jones Annexation, Hudson St. & Dakota Ave. (Annexation Map)

2 July 1959

DENVER gained small area from ARAPAHOE; Gibson St. & Blaine Ave. [not mapped]. (Annexation Map)

29 December 1959

DENVER gained from ARAPAHOE: Bansbach Annexation, Hampden Ave. & Happy Canyon; Glendale Area No. 8, Tennessee Ave. & Birch St. (Annexation Map)

13 September 1960

DENVER gained from ARAPAHOE; Garrett-Bromfield, Hampden Ave. & Holly St. (Annexation Map)

9 November 1960

DENVER gained from JEFFERSON; Bear Valley, Yale Ave. & Sheridan Blvd. (Annexation Map)

28 December 1960

DENVER gained from ADAMS; Airport Annexation. (Annexation Map)

14 February 1961

ARAPAHOE gained from DENVER by court ordered de-annexation: Hutchinson University Pl., Colorado Blvd. & Wesley Ave. (Annexation Map)

13 March 1961

DENVER gained from ARAPAHOE; Evans Ave. Annexation, Jewell Ave. & Quebec St. (Annexation Map)

8 May 1961

DENVER gained from JEFFERSON; Green Meadows, Evans Ave. & Sheridan Blvd. (Annexation Map)

13 June 1961

DENVER gained from ARAPAHOE: McMeen, Cherry Creek & Mississippi Ave.; Robinson Brick & Tile, Platte River Dr. & Yale Ave.; George Washington, Virginia Ave. & Kearney St. (Annexation Map)

3 July 1961

DENVER gained from ADAMS; Union Pacific, Smith Rd. & Havana St. (Annexation Map)

25 July 1961

DENVER gained from ARAPAHOE; Hutchinson University Pl., Colorado Blvd. & Wesley Ave. (Annexation Map)

7 August 1961

DENVER gained from ARAPAHOE; Fort Logan, Hampden Ave. & Lowell Blvd. (Annexation Map)

29 December 1961

DENVER gained from ARAPAHOE: Oaksdale No. 1, Oneida St. & Jewell Ave.; Third Christian Reformed Church, Wesley Ave. & Ash St.; Prince of Peace, Colorado Blvd. & Wesley Ave. (Annexation Map)

19 March 1962

DENVER gained from ARAPAHOE; College View, Federal Blvd. & Jewell Ave. (Annexation Map)

27 March 1962

DENVER gained from JEFFERSON; West Jewell, Depew St. & Jewell Ave. (Annexation Map)

31 July 1962

DENVER gained from JEFFERSON; West Bear Valley, Lamar St. & Yale Ave. (Annexation Map)

6 September 1962

DENVER gained from ARAPAHOE; Forest St., Leetsdale Dr. & Forest St. (Annexation Map)

11 September 1962

DENVER gained from ARAPAHOE; Centennial Estates, Lowell Blvd. & Wagon Trail Dr. (Annexation Map)

2 October 1962

DENVER gained from JEFFERSON; Inspiration Point Estates, Sheridan Blvd. & W. 52nd Ave. (Annexation Map)

15 October 1962

DENVER gained from ARAPAHOE; Garrett-Bromfield No. 2, Hampden Ave. & Quebec St. (Annexation Map)

15 April 1963

DENVER gained from ARAPAHOE; University Heights, Evans Ave. & Valley Hwy. (Annexation Map)

23 May 1963

DENVER gained from ARAPAHOE; Deane Buick, Colorado Blvd. & Mississippi Ave. (Annexation Map)

6 June 1963

DENVER gained from ADAMS; Marycrest, Federal Blvd. & W. 52nd Ave. (Annexation Map)

18 June 1963

DENVER gained from ARAPAHOE; Oakesdale No. 3, Jewell Ave. & Oneida St. (Annexation Map)

24 June 1963

DENVER gained from JEFFERSON; Bear Valley Church, Yale Ave. & S. Lamar St. (Annexation Map)

9 July 1963

DENVER gained from JEFFERSON; Bear Valley South, Kenyon Ave. & S. Sheridan Blvd. (Annexation Map)

6 August 1963

DENVER gained from ARAPAHOE: Elm St., Leetsdale Dr. & Elm St.; Centennial Acres Trumac, Federal Blvd. & W. Union Ave.; Harris, Niagara St. & Panorama Lane. (Annexation Map)

27 August 1963

DENVER gained from ARAPAHOE; East Mississippi, Quebec St. & Mississippi Ave. (Annexation Map)

4 September 1963

DENVER gained from ARAPAHOE: Hampden North, Monaco St. Pkwy. & Hampden Ave.; Hampden South, Quebec St. & Hampden Ave. (Annexation Map)

17 December 1963

DENVER gained small area from ARAPAHOE; Bruno, Colorado Blvd. & Arizona Ave. (Annexation Map)

30 December 1963

DENVER gained from ARAPAHOE; East Belleview, Quincy Ave. & Syracuse St.; Eastern Star, Highline Canal & Wesley Ave. (Annexation Map)

10 February 1964

DENVER gained from ARAPAHOE; Range View No. 2, Fulton St. & Mississippi Ave. (Annexation Map)

11 February 1964

DENVER gained from ADAMS; Stapleton East, Havana St. & E. 56th Ave. (Annexation Map)

27 April 1964

DENVER gained small area from ARAPAHOE; Galilee Baptist Church, Parker Road & Mississippi Dr. (Annexation Map)

11 May 1964

DENVER gained from ARAPAHOE; Range View #3, Mississippi Ave. & Havana St. (Annexation Map)

9 June 1964

DENVER gained from ARAPAHOE; Lowry, 6th Ave. & Dayton St. (Annexation Map)

24 June 1964

DENVER gained from ARAPAHOE [Hillcrest Reservoir, Happy Canyon Road & Monaco Blvd.] and JEFFERSON [Bear Valley South #2, Kenyon Ave. & Harlan St.; Bear Valley South #3, Kenyon Ave. & Sheridan Blvd.]. (Annexation Map)

21 July 1964

DENVER gained small areas from ARAPAHOE; Ames, Dahlia St. & C&S RR; Maddox, Vassar Ave. & Fairfax St.; Rieger, Evans Ave. & Grape St. (Annexation Map)

20 October 1964

DENVER gained from JEFFERSON; Runyan, Sheridan Blvd. & W. 10th Ave.; Crosby, Hampden Ave. & Lamar St. (Annexation Map)

16 November 1964

DENVER gained from ARAPAHOE; Myrtle Hill, Colorado Blvd. & Amherst Ave. (Annexation Map)

24 November 1964

DENVER gained from ARAPAHOE; Bethesda, Iliff Ave. & Birch St. (Annexation Map)

30 November 1964

DENVER gained from ADAMS; Stapleton West, 56th Ave. & Quebec St. (Annexation Map)

4 December 1964

DENVER gained from ARAPAHOE; Hallcraft, Hampden Ave. & Yosemite St. (Annexation Map)

8 December 1964

DENVER gained small area from ARAPAHOE; Warren Ave., Warren Ave. & Grape St. (Annexation Map)

31 December 1964

DENVER gained small area from ADAMS [Associated Grocers, Valley Hwy. & 52nd Ave.] and gained from ARAPAHOE [Dahlia-Iliff, S. Dahlia & E. Iliff Ave.; Ruby Hill, S. Pecos St. & W. Mexico Ave.]. (Annexation Map)

18 March 1965

DENVER gained from ARAPAHOE; Hampden Heights, Hampden Ave. & Yosemite St. (Annexation Map)

22 March 1965

DENVER gained from ARAPAHOE; Golden Key, Yosemite St. & Syracuse Way. (Annexation Map)

5 April 1965

DENVER gained from ARAPAHOE: Moore, Valley Hwy. & Yale Ave.; Dahlia-Evans, Dahlia St. & Evans Ave. (Annexation Map)

19 April 1965

DENVER gained from ARAPAHOE; Holly Ridge, Hampden Ave. & Monaco St. (Annexation Map)

3 May 1965

DENVER gained small area from ARAPAHOE; Barnes, Colorado Blvd. & Arizona Ave. (Annexation Map)

17 May 1965

DENVER gained from ARAPAHOE; Transfer Station, Cherry Creek, Jewell Ave. (extended) & Quebec St. DENVER lost to ARAPAHOE; Fort Logan, Hampden Ave. & Lowell Blvd., when the area was de-annexed by court order. (Annexation Map; "Elkins vs. Denver," in Pacific Reporter, 2d ser., vol. 402, 617-621)

30 June 1965

ARAPAHOE gained from DENVER: Centennial Estates, Lowell Blvd. & Wagon Trail Dr.; Centennial Trumac, Federal Blvd. & Union Ave., when the earlier 11 September 1962 and 6 August 1963 annexations of these areas were dismissed by court order. (Annexation Map)

12 July 1965

DENVER gained small area from ARAPAHOE; Moore #2, Vassar Ave. & Colo. State Hwy. 185. (Annexation Map)

23 August 1965

DENVER gained from ARAPAHOE; Rutter, Evans Ave. & Elm St. (Annexation Map)

13 September 1965

DENVER gained from ADAMS; Interstate, Havana St. & Interstate Hwy. 70. (Annexation Map)

27 September 1965

DENVER gained from ARAPAHOE; P.B.C., Sheridan Blvd. & Hampden Ave. (Annexation Map)

6 December 1965

DENVER gained from ARAPAHOE: Federal-Dartmouth, Dartmouth Ave. & Federal Blvd.; Kennedy Golf Course, Hampden Ave. & Havana St.; Jeffersonian Apartments, Iliff Ave. & Valley Hwy. (Annexation Map)

13 December 1965

DENVER gained small area from ADAMS [Union Pacific #2, Smith Road & Peoria St.] and gained from ARAPAHOE [Harris #2, Colorado Ave. & Oneida St.]. (Annexation Map)

27 December 1965

DENVER gained from ARAPAHOE; State Hospital, W. Oxford Ave. & S. Lowell Blvd. (Annexation Map)

21 January 1966

DENVER gained from ARAPAHOE; Holly Evans, Holly St. & Evans Ave. (Annexation Map)

28 March 1966

DENVER gained from ADAMS [Treatment Plant, Clifford Ave. between Lafayette St. & Downing St.] and gained from JEFFERSON [Fehlmann, W. Yale Ave. & S. Wadsworth Blvd.]. (Annexation Map)

18 April 1966

DENVER gained from ADAMS; Treatment Plant #2, Clifford Ave. (54th Ave.) between Downing St. & Ogden St. (Annexation Map)

1 July 1966

JEFFERSON gained from DENVER; Bear Valley South #1, #2, #3; W. Kenyon Ave. & S. Sheridan Blvd., when the area was de-annexed by court order. (Annexation Map)

22 August 1966

DENVER gained from JEFFERSON; Bear Valley Heights, W. Lehigh Ave. & S. Sheridan Blvd. (Annexation Map)

21 November 1966

DENVER gained from ARAPAHOE; Cherry Creek #4, Yale Ave. & S. Galena St. and General Motors, Warren Ave. & S. Dahlia St. (Annexation Map)

27 December 1966

DENVER gained from ARAPAHOE; Teen City, Iliff Ave. & S. Parker Road and Cherry Creek Galleries #1, Cherry Creek Row & Jewell Ave. Ext. (Annexation Map)

16 January 1967

DENVER gained from JEFFERSON; Bear Valley Heights #2, W. Kenyon Ave. Ext. & S. Sheridan Blvd. (Annexation Map)

1 November 1967

ARAPAHOE gained small area from DENVER when .68 acres (1st Ave. & Dayton St.) was de-annexed by court order [too small to map]. (Annexation Map)

11 December 1967

DENVER gained small area from ARAPAHOE; Glasier, Kentucky Ave. & Cherry Creek Row. (Annexation Map)

22 January 1968

DENVER gained from ARAPAHOE [Belquince, Quincy Ave. & Valley Highway] and gained from JEFFERSON [Bear Valley Park, W. Teller Ave. & Bear Creek]. (Annexation Map)

19 February 1968

DENVER gained small area from ARAPAHOE; Golden Key Park, S. Syracuse Way & S. Xanthia St. (Annexation Map)

13 May 1968

DENVER gained small area from ADAMS; Marycrest #2, W. 54th & Columbine Road. (Annexation Map)

9 September 1968

DENVER gained from ARAPAHOE; Decatur-Dartmouth, W. Dartmouth Ave. & S. Decatur St. (Annexation Map)

30 December 1968

DENVER gained from ARAPAHOE; Glasier #2, Kentucky Ave. & Cherry Creek Row. (Annexation Map)

24 March 1969

DENVER gained from ARAPAHOE [Floyd-Federal, W. Floyd Ave. & S. Federal Blvd.] and gained from JEFFERSON [W. Inspiration Point, W. 52nd Ave. & Jay St. Ext.]. (Annexation Map)

9 September 1969

DENVER gained from JEFFERSON; Sheridan-Kenyon; S. Sheridan Blvd. & W. Hampden Ave. (Annexation Map)

21 November 1969

DENVER gained small area from JEFFERSON; Fehlman #2, W. Vassar Ave. & East of S. Wadsworth. (Annexation Map)

15 December 1969

DENVER gained from JEFFERSON; Pinehurst, W. Quincy Ave. & S. Sheridan Blvd. (Annexation Map)

29 December 1969

DENVER gained from ARAPAHOE; Centennial Estates #2, W. Wagon Trail Dr. & S. Perry St. (Annexation Map)

6 January 1970

DENVER gained from ADAMS [Stapleton North, 56th Ave. & Yosemite St.] and gained from ARAPAHOE [Havana-Parker, S. Havana St. & Parker Road.]. (Annexation Map)

9 February 1970

DENVER gained from JEFFERSON; Marston Lake #1, W. Quincy Ave. & Harlan St. (Annexation Map)

16 March 1970

DENVER gained from ARAPAHOE; Conway, S Quebec St. & Jewell Ave. (Annexation Map)

26 March 1970

DENVER gained from JEFFERSON; Marston Lake #2, W. Quincy Ave. & Wadsworth Blvd.-Sheridan Blvd. (Annexation Map)

13 April 1970

DENVER gained small area from ARAPAHOE; Belquince #2, S. Monaco Pkwy. & Belleview Ave. (Annexation Map)

27 April 1970

DENVER gained from ARAPAHOE; Parker Road South, S. Parker Road & West of I-255. (Annexation Map)

1 July 1970

DENVER gained small area from ARAPAHOE; Galilee Baptist Church #2, S. Rosemary Way & Mississippi Dr. (Annexation Map)

13 July 1970

DENVER gained small area from JEFFERSON; Bear Valley Enclave, S. Lamar St. & W. Yale Ave. (Annexation Map)

September 1970

In September 1970 DOLORES gained from MONTEZUMA by agreement of both county boards of commissioners. (Loretta Murphy, Montezuma Co. Mapping Dept., email, 26 November 2007)

9 September 1970

DENVER gained small area from JEFFERSON; Bear Valley Heights Enclave, S. Harlan & W. Kenyon. (Annexation Map)

28 September 1970

DENVER gained from ADAMS; Franklin-54th, Franklin St. & 54th Ave. (Annexation Map)

30 November 1970

DENVER gained from ARAPAHOE; Dahlia-Iliff #2, S. Dahlia St. & Iliff Ave. (Annexation Map)

28 December 1970

DENVER gained from ARAPAHOE; Parker Road South #2, S. Parker Road & West of I-225. (Annexation Map)

9 October 1971

DENVER gained from JEFFERSON; Cavalier Annexation, W. Hampden Ave. & S. Harlan. (Annexation Map)

2 November 1971

DENVER gained from ARAPAHOE; Valley Highway, Evans Ave. & Valley Highway and Marcor, Iliff Ave. & S. Dayton St. (Annexation Map)

11 November 1971

DENVER gained from ADAMS; North Franklin, 54th Ave. & Franklin St. (Annexation Map)

22 November 1971

DENVER gained from ARAPAHOE; Quebec-Quincy, Quincy Ave. & Quebec St. and Tech. Center #1, I-224 & S. Quebec St. (Annexation Map)

27 December 1971

DENVER gained from ARAPAHOE; Tech. Center #2, Union Ave. & S. Quebec St. DENVER gained small area from ARAPAHOE, Harris Annex #3, Asbury Ave. & S. Oneida St. [too small to map]. (Annexation Map)

31 December 1971

JEFFERSON gained from DENVER when Cavalier Annex area (annexed to DENVER on 9 October 1971) was de-annexed from DENVER, but the entire area (with a small exception) was immediately re-annexed to DENVER [no mappable change]. (Annexation Map)

6 June 1972

DENVER gained from ADAMS; Pump Station-56th Ave., 56th Ave. & Roslyn St. (Annexation Map)

27 July 1972

DENVER gained small area from ARAPAHOE; South Pontiac Way, Asbury Ave. & S. Pontiac Way. (Annexation Map)

3 August 1972

DENVER gained from JEFFERSON; West Marston, W. Quincy Ave. & S. Wadsworth. (Annexation Map)

8 November 1972

DENVER gained from JEFFERSON; Vaughn, W. Hampden Ave. & S. Harlan St. (Annexation Map)

5 January 1973

DENVER gained from ARAPAHOE; Beverly Manor, W. Floyd Ave. & S. Federal Blvd. (Annexation Map)

10 January 1973

DENVER gained from JEFFERSON; Park West, W. Stanford Ave. & S. Kipling St. (Annexation Map)

by 31 December 1973

DENVER gained small area from ADAMS; W. 52nd Ave. & Lincoln St. (Annexation Map)

by 1979

DENVER gained from ADAMS. (USGS, 7.5 Minute Series, Sable Quadrangle, edition of 1965 [photorevised 1971] and edition of 1965 [photorevised 1979])

by 1980

DENVER gained from ARAPAHOE and JEFFERSON. (USGS, 7.5 Minute Series, various Colorado Quadrangles, 1971-2000)

1 July 1982

ROUTT boundaries were clarified, placing its boundary with GARFIELD, GRAND, and RIO BLANCO on public land survey lines. This act brought the Revised Statutes into compliance with the boundary lines that had long been observed [no change]. (Colo. Laws 1982, 53d sess., ch. 127, pp. 480-481)

16 March 1984

Boundary between OURAY and SAN MIGUEL was redefined to correct mistake of 17 April 1917 [no change]. (Colo. Laws 1984, 54th sess., ch. 230, pp. 816-817)

17 May 1988

DENVER gained from ADAMS; Denver International Airport annexation. Referendum held 17 May 1988. (Dempsey, 142)

by 1994

DENVER gained small area from ARAPAHOE [Mississippi Ave. & S. Tamarac] and gained from JEFFERSON [W. Grant Ranch Blvd. & S. Estes St.]. (USGS, 7.5 Minute Series, various Colorado Quadrangles, 1980-1994)

15 November 2001

BROOMFIELD created from ADAMS, BOULDER, JEFFERSON, and WELD. (Colo. Laws 2001, 63d sess., ch. 103, pp. 256-274)