Utah Atlas of Historical County Boundaries
John H. Long, Editor; Peggy Tuck Sinko, Associate Editor and Utah Historical Compiler; Brandon Plewe, Utah Historical Compiler; John P. Ford, Nevada and Utah 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; Robert Will, Cartographic Assistant
Copyright The Newberry Library 2008
22 February 1819
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, giving Spanish Mexico clear possession of present Utah. (Parry, 70:1-30; Paullin, 63-64, plates 94-95; Van Zandt, 26-27)
24 August 1821
Mexico gained its independence from Spain. Present Utah, which 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)
22 July 1847
Mormon pioneers entered the Salt Lake Valley in present Utah while it was still under the jurisdiction of the Republic of Mexico. Brigham Young and additional travelers arrived two days later. (Brown, Cannon, and Jackson, 82)
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 was the true boundary between Mexico and Texas. The area of present Utah became unorganized federal territory in the United States. (Parry, 102: 29-59; U.S. Stat., vol. 9[1848]/pp. 922-943)
12 March 1849
Mormon leaders organized a government, and settlers voted this date to form the state of Deseret. (Brown, Cannon, and Jackson, 90-91)
2 July 1849
The General Assembly of the newly proposed state of Deseret met on 2 July 1849. The large state was to include almost all of Utah and parts of present Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, and Wyoming, but this proposal never gained widespread support in the U.S. Congress. (Atlas of Utah, 160-161; Brown, Cannon, and Jackson, 90-91; Swindler, 9:375-381)
31 January 1850
State of Deseret created six counties:
GREAT SALT LAKE (now SALT LAKE) created from non-county area. (Morgan, 47-48, 144; HRS Utah, Weber, 9)
LITTLE SALT LAKE (now IRON) created from non-county area to cover Little Salt Lake Valley; LITTLE SALT LAKE not fully organized. (Morgan, 47-48, 145)
SANPETE created from non-county area to cover the San Pete Valley. (Morgan, 47-48, 144)
TOOELE (spelled TUILLA here) created from non-county area to cover the Tuilla/Tooele Valley; TUILLA not fully organized, attached to GREAT SALT LAKE "for judicial, revenue, and election purposes." (Morgan, 47-48, 145)
UTAH created from non-county area to cover the Utah Valley. (Morgan, 47-48, 144)
WEBER created from non-county area. (Morgan, 47-48, 144; HRS Utah, Weber, 9)
9 September 1850
The United States created Utah Territory from the territory ceded by Mexico in the Treaty of Guadalupe-Hidalgo (1848), from territory to be purchased from the state of Texas in December 1850, and from unorganized federal territory. Utah Territory included all of present Utah and parts of present Colorado, Nevada, and Wyoming. Governmental functions of the state of Deseret continued. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452 and ch. 51[1850]/pp. 453-458; Van Zandt, 159)
5 October 1850
DAVIS created by the state of Deseret from GREAT SALT LAKE (now SALT LAKE) and WEBER. (Morgan, 54-55, 152-153)
3 December 1850
LITTLE SALT LAKE renamed IRON, and gained non-county area in the state of Deseret. (Morgan, 56-57, 157)
17 January 1851
IRON fully organized. (Dalton, 27-28)
5 April 1851
The state of Deseret was dissolved by its General Assembly, upon recommendation of Brigham Young. Counties originally created by Deseret: DAVIS, GREAT SALT LAKE (now SALT LAKE), IRON, SANPETE, TOOELE, UTAH, and WEBER continued to operate. (Brown, Cannon, and Jackson, 90; Powell, 139)
10 June 1851
TOOELE (originally TUILLA) fully organized; detached from GREAT SALT LAKE (now SALT LAKE). (Tooele County Daughters of Utah Pioneers, 24)
4 October 1851
Legislative Assembly of Utah Territory legalized the standing laws of the state of Deseret until such time as they were superseded by laws of Utah Territory; counties created by the state of Deseret continued to operate. (Utah Terr. Laws 1851, 1st sess., p. 222; Morgan, 88)
MILLARD created by Utah Territory from non-county area in the Pavant Valley. (Utah Terr. Laws 1851, 1st sess., pp. 161-162)
3 March 1852
All non-county area in Utah Territory was eliminated when Utah Territory created four new counties and redefined boundaries of eight counties to cover all areas of the territory. (Utah Terr. Laws 1851, 1st sess., pp. 162-163; for sections and pages of particular counties see following citations)
DESERT (Utah Territory, extinct) created from non-county area and part of TOOELE; included parts of present Utah and Nevada. DESERT not fully organized, attached to WEBER "for election, revenue, and judicial purposes." (sec. 3/p. 162)
GREEN RIVER (Utah Territory, extinct) created from non-county area; included parts of present Utah, Colorado, and Wyoming. GREEN RIVER not fully organized, attached to GREAT SALT LAKE (now SALT LAKE) "for election, revenue, and judicial purposes." (sec. 4/pp. 162-163)
JUAB created from UTAH and non-county area; included parts of present Utah and Nevada. (sec. 9/p. 163)
WASHINGTON created from non-county area and IRON; included parts of present Utah, Colorado, and Nevada. WASHINGTON not fully organized, attached to IRON "for election, revenue, and judicial purposes." (sec. 13/p. 164)
DAVIS gained from GREAT SALT LAKE (now SALT LAKE), lost to WEBER. (sec. 2/p. 162)
GREAT SALT LAKE gained from TOOELE and non-county area; exchanged with UTAH; lost to DAVIS. GREAT SALT LAKE included parts of present Utah and Colorado. GREEN RIVER (Utah Territory, extinct) and Islands in the Great Salt Lake south of WEBER were attached to GREAT SALT LAKE "for election, revenue, and judicial purposes." (secs. 4-6/pp. 162-163)
IRON gained non-county area, lost to creation of WASHINGTON; included parts of present Utah, Colorado, and Nevada. WASHINGTON not fully organized, attached to IRON "for election, revenue, and judicial purposes." (secs. 12-13/p. 164)
MILLARD gained from SANPETE and non-county area; included parts of present Utah and Nevada. (sec. 10/pp. 163-164)
SANPETE gained non-county area, lost to MILLARD; included parts of present Utah and Colorado. (sec. 11/p. 164)
TOOELE gained non-county area, lost to DESERT (Utah Territory, extinct), GREAT SALT LAKE (now SALT LAKE), and UTAH; included parts of present Utah and Nevada. (sec. 8/p. 163)
UTAH gained non-county area, exchanged with GREAT SALT LAKE (now SALT LAKE); lost to JUAB and SANPETE; included parts of present Utah and Colorado. (sec. 7/p. 163)
WEBER gained from DAVIS and non-county area; included parts of present Utah and Nevada. DESERT (Utah Territory, extinct) not fully organized, attached to WEBER "for election, revenue, and judicial purposes." (secs. 1, 3/p. 162)
13 January 1854
DAVIS gained from GREEN RIVER (Utah Territory, extinct). (Utah Terr. Laws 1853, 3d sess., pp. 14-15)
GREEN RIVER (Utah Territory, extinct) gained from GREAT SALT LAKE (now SALT LAKE), SANPETE, and UTAH. GREAT SALT LAKE and UTAH both eliminated from present Colorado. (Utah Terr. Laws 1853, 3d sess., pp. 14-15)
SUMMIT created by Utah Territory from GREEN RIVER (Utah Territory, extinct) and GREAT SALT LAKE (now SALT LAKE); SUMMIT included territory in present Utah and Wyoming. SUMMIT not fully organized, attached to GREAT SALT LAKE "for election, revenue, and judicial purposes." (Utah Terr. Laws 1853, 3d sess., pp. 14-15)
17 January 1854
CARSON (Utah Territory, extinct) created by Utah Territory from IRON, JUAB, MILLARD, and TOOELE; CARSON not fully organized, attached to MILLARD "for election, revenue, and judicial purposes." CARSON was located entirely in present Nevada. (Utah Terr. Laws 1853, 3rd sess., p. 19)
15 June 1854
GREEN RIVER (Utah Territory, extinct) fully organized, detached from GREAT SALT LAKE (now SALT LAKE). (Gowans and Campbell, 63)
10 January 1855
DAVIS gained from WEBER. (Utah Terr. Laws 1854, 4th sess., ch. 85/pp. 279-280)
GREAT SALT LAKE (now SALT LAKE) gained from DAVIS. (Utah Terr. Laws 1854, 4th sess., ch. 85/pp. 279-280)
18 January 1855
JUAB exchanged with SANPETE. (Utah Terr. Laws 1854, 4th sess., ch. 81/pp. 276-277)
2 October 1855
CARSON (Utah Territory, extinct) fully organized; detached from MILLARD. (History of Nevada, 38)
5 January 1856
BEAVER created by Utah Territory from IRON; BEAVER included parts of present Utah, Colorado, and Nevada. (Utah Terr. Laws 1855, 5th sess., sec. 9/p. 7)
BOX ELDER created by Utah Territory from WEBER. (Utah Terr. Laws 1855, 5th sess., sec. 6/pp. 6-7)
CACHE created by Utah Territory from SUMMIT and WEBER; CACHE included territory in present Utah and Wyoming. CACHE not fully organized. (Utah Terr. Laws 1855, 5th sess., sec. 5/p. 6)
CARSON (Utah Territory, extinct) gained from DESERT (Utah Territory, extinct) and WEBER. (Utah Terr. Laws 1855, 5th sess., sec. 1/p. 5)
CEDAR (Utah Territory, extinct) created by Utah Territory from UTAH. (Utah Terr. Laws 1855, 5th sess., sec. 8/p. 7)
GREASEWOOD (Utah Territory, extinct) created by Utah Territory from WEBER. GREASEWOOD not fully organized, attached to MALAD (Utah Territory, extinct) "for election, revenue, and judicial purposes." (Utah Terr. Laws 1855, 5th sess., sec. 4/p. 6 and p. 8)
HUMBOLDT (Utah Territory, extinct) created by Utah Territory from DESERT (Utah Territory, extinct), JUAB, TOOELE, and WEBER; HUMBOLDT was located entirely in present Nevada. HUMBOLDT not fully organized, attached to TOOELE "for election, revenue, and judicial purposes." (Utah Terr. Laws 1855, 5th sess., sec. 2/pp. 5-6 and p. 8)
MALAD (Utah Territory, extinct) created by Utah Territory from WEBER. GREASEWOOD (Utah Territory, extinct) attached to MALAD "for election, revenue, and judicial purposes." (Utah Terr. Laws 1855, 5th sess., sec. 7/p. 7 and p. 8)
ST. MARY'S (Utah Territory, extinct) created by Utah Territory from DESERT (Utah Territory, extinct), JUAB, TOOELE, and WEBER. ST MARY'S was located entirely in present Nevada. ST. MARY'S not fully organized, attached to TOOELE "for election, revenue, and judicial purposes." (Utah Terr. Laws 1855, 5th sess., sec. 3/p. 6 and p. 8)
WASHINGTON gained from IRON 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)
DESERT, JUAB, TOOELE and WEBER all eliminated from present Nevada. (Utah Terr. Laws 1855, 5th sess., pp. 5-8)
12 January 1856
SHAMBIP (Utah Territory, extinct) created by Utah Territory from TOOELE. (Utah Terr. Laws 1855, 5th sess., pp. 7-8)
23 February 1856
WASHINGTON fully organized, detached from IRON. (Larson, 26)
14 January 1857
CARSON (Utah Territory, extinct) was disorganized and attached to GREAT SALT LAKE (now SALT LAKE) "for election, revenue and judicial purposes." (Utah Terr. Laws 1856, 6th sess., pp. 11-14)
4 April 1857
CACHE fully organized. (Ricks, 90)
22 December 1857
GREEN RIVER (Utah Territory, extinct) was disorganized and attached to GREAT SALT LAKE (now SALT LAKE) "for election, revenue and judicial purposes" because most settlers had left the area. (Utah Terr. Laws 1857, 7th sess., p. 1)
17 January 1859
CARSON (Utah Territory, extinct) and GREEN RIVER (Utah Territory, extinct) were reorganized and detached from GREAT SALT LAKE (now SALT LAKE). (Utah Terr. Laws 1858, 8th sess., ch. 11/pp. 19-20)
HUMBOLDT (Utah Territory, extinct) and ST. MARY'S (Utah Territory, extinct) detached from TOOELE, attached to CARSON "for election, revenue and judicial purposes." (Utah Terr. Laws 1858, 8th sess., ch. 11/pp. 19-20)
24 October 1859
Voters in the area of present Colorado 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 MOUNTAIN (Jefferson Territory, extinct); MOUNTAIN included territory in present Colorado and Utah, and overlapped part of Utah Territory [BEAVER, GREEN RIVER (Utah Territory, extinct), IRON, SANPETE, and WASHINGTON]. (Jefferson Terr. Laws 1859, 1st sess., sec. 12/ p. 192)
The extralegal Territory of Jefferson created SARATOGA (Jefferson Territory, extinct). SARATOGA was located entirely in present Colorado, but overlapped part of Utah Territory [GREEN RIVER (Utah Territory, extinct) and SANPETE]. (Jefferson Terr. Laws 1859, 1st sess., sec. 7, p. 191)
18 January 1861
CARSON (Utah Territory, extinct) boundaries were redefined [no change]. (Utah Terr. Laws 1861, 10th sess., p. 19)
DESERT (Utah Territory, extinct), GREASEWOOD (Utah Territory, extinct), JUAB, SHAMBIP (Utah Territory, extinct), and TOOELE all gained from ST. MARY'S (Utah Territory, extinct); all included territory in present Utah and Nevada. (Utah Terr. Laws 1861, 10th sess., p. 19)
HUMBOLDT (Utah Territory, extinct) gained from BEAVER, IRON, MILLARD, and WASHINGTON; HUMBOLDT remained attached to CARSON (Utah Territory, extinct). (Utah Terr. Laws 1861, 10th sess., p. 19)
ST. MARY'S (Utah Territory, extinct) gained from BEAVER, IRON, MILLARD, and WASHINGTON. ST. MARY'S remained attached to CARSON (Utah Territory, extinct). (Utah Terr. Laws 1861, 10th sess., p. 19)
28 February 1861
The United States created Colorado Territory from Nebraska, New Mexico, and Utah Territories, and from the former Kansas Territory. BEAVER, GREEN RIVER (Utah Territory, extinct), IRON, SAN PETE, and WASHINGTON 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)
2 March 1861
The United States created Nevada Territory from Utah Territory. CARSON (Utah Territory, extinct) and HUMBOLDT (Utah Territory, extinct) both eliminated, ending attachment of ST. MARY'S (Utah Territory, extinct) to CARSON. (U.S. Stat., vol. 12, ch. 83[1861], pp. 209-210; Van Zandt, 158-160)
GREEN RIVER (Utah Territory, extinct) lost to Nebraska Territory when Nebraska Territory gained area in present Wyoming from Utah Territory. (U.S. Stat., vol. 12, ch. 86[1861], pp. 239-244; Van Zandt, 134, 136-137)
4 March 1861
SUMMIT fully organized; detached from GREAT SALT LAKE (now SALT LAKE). (Summit County Record Book A, p. 1)
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; MOUNTAIN (Jefferson Territory) and SARATOGA (Jefferson Territory) eliminated. Overlap of Utah Territory by SARATOGA ended technically on 28 February 1861 when Utah Territory lost to the creation of Colorado Territory. (U.S. Stat., vol. 12, ch. 59[1861]/pp. 172-177; Smiley, 321-322)
17 January 1862
BEAVER gained from MILLARD, SANPETE, and ST. MARY'S (Utah Territory, extinct). (Utah Terr. Laws 1861, 11th sess., sec. 3/p. 47)
BOX ELDER gained all of GREASEWOOD (Utah Territory, extinct) and MALAD (Utah Territory, extinct); gained from DESERT (Utah Territory, extinct), TOOELE, and ST. MARY'S (Utah Territory, extinct). BOX ELDER included territory in present Utah and Nevada. (Utah Terr. Laws 1861, 11th sess., sec. 12/p. 49)
CACHE gained from BOX ELDER and SUMMIT, exchanged with GREEN RIVER (Utah Territory, extinct). (Utah Terr. Laws 1861, 11th sess., sec. 16/p. 50)
GREAT SALT LAKE (now SALT LAKE) gained from CEDAR (Utah Territory, extinct) and DAVIS; exchanged with UTAH. All islands in the Great Salt Lake were attached to GREAT SALT LAKE "for election, revenue, and judicial purposes." (Utah Terr. Laws 1861, 11th sess., secs. 9, 18/pp. 48, 50)
GREEN RIVER (Utah Territory, extinct) exchanged with CACHE and SUMMIT. (Utah Terr. Laws 1861, 11th sess., sec. 17/p. 50)
IRON gained from ST. MARY'S (Utah Territory, extinct) and WASHINGTON. (Utah Terr. Laws 1861, 11th sess., sec. 2/p. 46)
JUAB gained small areas from CEDAR (Utah Territory, extinct) and SHAMBIP (Utah Territory, extinct); exchanged with MILLARD. (Utah Terr. Laws 1861, 11th sess., sec. 6/pp. 47-48)
MILLARD gained from ST. MARY'S (Utah Territory, extinct). (Utah Terr. Laws 1861, 11th sess., sec. 4/p. 47)
MORGAN created by Utah Territory from DAVIS, GREAT SALT LAKE (now SALT LAKE), SUMMIT, and WEBER. (Utah Terr. Laws 1861, 11th sess., sec. 15/p. 50)
SANPETE gained from GREEN RIVER (Utah Territory, extinct) and MILLARD; exchanged with UTAH. (Utah Terr. Laws 1861, 11th sess., sec. 5/p. 47)
SUMMIT gained from DAVIS and GREAT SALT LAKE (now SALT LAKE). (Utah Terr. Laws 1861, 11th sess., sec. 14/pp. 49-50)
TOOELE gained from CEDAR (Utah Territory, extinct), DESERT (Utah Territory, extinct), GREAT SALT LAKE (now SALT LAKE), JUAB, SHAMBIP (Utah Territory, extinct), and ST. MARY'S (Utah Territory, extinct). (Utah Terr. Laws 1861, 11th sess., sec. 13/p. 49)
UTAH gained from CEDAR (Utah Territory, extinct) and JUAB. (Utah Terr. Laws 1861, 11th sess., sec. 7/p. 48)
WASATCH created by Utah Territory from GREAT SALT LAKE (now SALT LAKE), GREEN RIVER (Utah Territory, extinct), SANPETE, SUMMIT, and UTAH. (Utah Terr. Laws 1861, 11th sess., sec. 8/p. 48)
WASHINGTON gained from ST. MARY'S (Utah Territory, extinct). (Utah Terr. Laws 1861, 11th sess., sec. 1/p. 46)
WEBER gained from BOX ELDER and SUMMIT; DESERT eliminated, ending its attachment to WEBER. (Utah Terr. Laws 1861, 11th sess., secs. 11-13/p. 49)
14 July 1862
Nevada Territory gained from BEAVER, BOX ELDER, IRON, MILLARD, TOOELE, and WASHINGTON when Nevada Territory gained from Utah Territory. (U.S. Stat., vol. 12, ch. 173 [1862], p. 575; Van Zandt, 158-160)
16 January 1864
KANE created by Utah Territory from WASHINGTON. (Utah Terr. Laws 1863, 13th sess., pp. 18-19)
RICHLAND (now RICH) created by Utah Territory from CACHE; RICHLAND included territory in present Utah and Wyoming. RICHLAND not fully organized. (Utah Terr. Laws 1863, 13th sess., pp. 18-19)
5 May 1864
RICHLAND (now RICH) fully organized. (Parson, 274)
16 January 1865
PIUTE created by Utah Territory from BEAVER. (Utah Terr. Laws 1864, 14th sess., p. 16)
SEVIER created by Utah Territory from SANPETE. (Utah Terr. Laws 1864, 14th sess., p. 16)
10 January 1866
Utah Territory passed a single act to change or redefine the boundaries of 21 counties. (Utah Terr. Laws 1865, 15th sess., ch. 146, secs. 1-22/pp. 207-209; for sections and pages on particular counties see following)
BEAVER boundaries redefined [no change]. (sec. 4/p.207)
BOX ELDER boundaries were redefined [no change]. (sec. 16/p. 209)
CACHE boundaries were redefined [no change]. (sec. 20/p. 209)
DAVIS boundaries were redefined [no change]. (sec. 14/pp. 208-209)
GREAT SALT LAKE (now SALT LAKE) boundaries were redefined [no change]. (secs. 12-13/p. 208)
GREEN RIVER (Utah Territory, extinct) boundaries were redefined [no change]. (sec. 22/p. 209)
JUAB exchanged small areas with SANPETE, lost to MILLARD. (secs. 8-9/p. 208)
KANE boundaries were redefined [no change]. (sec. 1/p. 207)
MILLARD gained from JUAB. (secs. 6, 8/p. 208)
MORGAN boundaries were redefined [no change]. (sec. 19/p. 209)
RICHLAND (now RICH) boundaries were redefined [no change]. (sec. 21/p. 209)
SEVIER gained from PIUTE. (secs. 5, 7/pp. 207-208)
SUMMIT boundaries were clarified [no change]. (sec. 18/p. 209)
TOOELE boundaries were redefined [no change]. (sec. 17/p. 209)
UTAH boundaries were redefined [no change]. (sec. 10/p. 208)
WASATCH boundaries were clarified [no change]. (sec. 11/p. 208)
WASHINGTON gained from IRON. (secs. 2-3/p. 207)
WEBER boundaries were redefined [no change]. (sec. 15/p. 209)
5 May 1866
The state of Nevada gained from Utah Territory. Utah counties of: BEAVER, BOX ELDER, IRON, MILLARD, TOOELE, and WASHINGTON all eliminated from present Nevada. (U.S. Stat., vol. 14, ch. 73[1866]/p. 43; Van Zandt, 158-159)
29 January 1868
GREAT SALT LAKE renamed SALT LAKE. (Utah Terr. Laws 1868, 17th sess., ch. 3/p. 2)
RICHLAND renamed RICH. (Utah Terr. Laws 1868, 17th sess., ch. 2/p. 1)
21 February 1868
JUAB boundary with SANPETE was clarified [no change]. (Utah Terr. Laws 1868, 17th sess., ch. 23/p. 26)
25 July 1868
The United States created Wyoming Territory from Dakota, Idaho, and Utah Territories. GREEN RIVER (Utah Territory, extinct), RICH, and SUMMIT all lost to Wyoming Territory. (U.S. Stat., vol. 15, ch. 235[1868], secs. 1, 17/pp. 178, 183; Van Zandt, 136, 144)
28 January 1869
Eastern boundary of UTAH was clarified [no change]. (Utah Terr. Laws 1869, 18th sess., ch. 1/p. 1)
18 February 1869
RIO VIRGEN (Utah Territory, extinct) created by Utah Territory from WASHINGTON. Due to lack of geographical knowledge about the precise location of the southwestern boundary of Utah Territory, this county covered only a very small area, which was not the intention of the territorial legislature. (Utah Terr. Laws 1869, 18th sess., ch. 10/p. 7; Atlas of Utah, 163-164)
1 August 1869
KANE gained from WASHINGTON. Act passed 19 February 1869; took effect 1 August 1869. (Utah Terr. Laws 1869, 18th sess., ch. 18/p. 17)
18 February 1870
JUAB gained from TOOELE. (Utah Terr. Laws 1870, 19th sess., p. 127)
16 February 1872
RICH gained small area from SUMMIT near town of Wasatch. (Utah Terr. Laws 1872, 20th sess., ch. 25, p. 40)
SUMMIT gained all of GREEN RIVER (Utah Territory, extinct); GREEN RIVER eliminated. (Utah Terr. Laws 1872, 20th sess., ch. 19, sec. 1/p. 28)
WASHINGTON gained all of RIO VIRGEN (Utah Territory, extinct); RIO VIRGEN eliminated. (Utah Terr. Laws 1872, 20th sess., ch. 19, sec. 2/p. 28)
12 February 1880
EMERY created by Utah Territory from SANPETE, SEVIER, and a narrow strip of PIUTE. SEVIER was temporarily divided into 2 parts. (Utah Terr. Laws 1880, 24th sess., ch. 4/pp. 4-5)
17 February 1880
EMERY gained from PIUTE, SANPETE, and SEVIER. SEVIER no longer divided into 2 parts. (Utah Terr. Laws 1880, 24th sess., ch. 9/pp. 10-11)
SAN JUAN created by Utah Territory from IRON, KANE, and PIUTE. (Utah Terr. Laws 1880, 24th sess., ch. 9/pp. 10-11)
18 February 1880
BOX ELDER gained part of the islands and waters of Great Salt Lake that had previously been attached to SALT LAKE, and gained from WEBER. (Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 4/pp. 16-17)
DAVIS gained part of the islands and waters of Great Salt Lake that had previously been attached to SALT LAKE. (Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 2/p. 16)
SALT LAKE gained part of the islands and waters of Great Salt Lake that had previously been attached to SALT LAKE. (Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 1/pp. 15-16)
TOOELE gained part of the islands and waters of Great Salt Lake that had previously been attached to SALT LAKE. (Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 5/p. 17)
UINTAH created by Utah Territory from SANPETE, SUMMIT, and WASATCH. (Utah Terr. Laws 1880, 24th sess., ch. 10/pp. 11-12)
UTAH gained from SANPETE. (Utah Terr. Laws 1880, 24th sess., ch. 16/pp. 18-19)
WASATCH gained from SANPETE. (Utah Terr. Laws 1880, 24th sess., ch. 16/pp. 18-19)
WEBER gained part of the islands and waters of Great Salt Lake that had previously been attached to SALT LAKE. (Utah Terr. Laws 1880, 24th sess., ch. 14, sec. 3/p. 16)
9 March 1882
GARFIELD created by Utah Territory from IRON. (Utah Terr. Laws 1882, 25th sess., ch. 52, pp. 98-101)
1 January 1883
GARFIELD boundary with KANE was adjusted to run on public land survey lines [not mapped]. (Utah Terr. Laws 1882, 25th sess., ch. 52, pp. 98-101)
IRON gained from KANE, exchanged with WASHINGTON. Boundary with BEAVER was adjusted to run on public land survey lines [no mappable change]. Act passed 9 March 1882; took effect 1 January 1883. (Utah Terr. Laws 1882, 25th sess., ch. 52, pp. 98-101)
WASHINGTON gained from KANE. (Utah Terr. Laws 1882, 25th sess., ch. 52, pp. 98-101)
13 March 1884
GARFIELD gained from IRON. (Utah Terr. Laws 1884, 26th sess., ch. 40, p. 58)
UTAH gained from WASATCH. (Utah Terr. Laws 1884, 26th sess., ch. 39, p. 57)
6 March 1888
JUAB gained from MILLARD and gained small area from SANPETE. Boundary with SANPETE was uncertain and ambiguous [line is estimated here]. (Utah Terr. Laws 1888, 28th sess., ch. 29, pp. 44-46)
10 March 1890
SANPETE gained from SEVIER. (Utah Terr. Laws 1890, 29th sess., ch. 16, pp. 13-14)
13 March 1890
GRAND created by Utah Territory from EMERY. (Utah Terr. Laws 1890, 29th sess., ch. 60, pp. 92-93)
SANPETE gained from EMERY. (Utah Terr. Laws 1890, 29th sess., ch. 61, p. 94)
27 February 1892
GRAND gained from UINTAH. (Utah Terr. Laws 1892, 30th sess., ch. 16, p. 16)
10 March 1892
IRON gained from WASHINGTON. (Utah Terr. Laws 1892, 30th sess., ch. 45, p. 47)
WAYNE created by Utah Territory from PIUTE. (Utah Terr. Laws 1892, 30th sess., ch. 71, pp. 79-81)
8 March 1894
Boundary between JUAB and TOOELE was adjusted to run on the second standard parallel south [no mappable change]. (Utah Terr. Laws 1894, 31st sess., ch. 35, pp. 31-32)
CARBON created by Utah Territory from EMERY. (Utah Terr. Laws 1894, 31st sess., ch. 58, pp. 82-83)
16 July 1894
The United States Congress passed an act enabling the citizens of Utah to form a state government and be admitted to the Union. (U.S. Stat., vol. 28, ch. 138 [1894]/pp. 107-112; Van Zandt, 159)
4 January 1896
The United States created the state of Utah from Utah Territory. BEAVER, BOX ELDER, CACHE, CARBON, DAVIS, EMERY, GARFIELD, GRAND, IRON, JUAB, KANE, MILLARD, MORGAN, PIUTE, RICH, SALT LAKE, SAN JUAN, SANPETE, SEVIER, SUMMIT,TOOELE, UINTAH, UTAH, WASATCH, WASHINGTON, WAYNE, and WEBER all became counties in the state of Utah. (U.S. Stat., vol. 28, ch. 138 [1894]/pp. 107-112; U.S. Stat., vol. 29, procl. no. 9, [1896]/pp. 876-877; Van Zandt, 159)
23 March 1901
Legislature authorized GRAND to gain all of SAN JUAN, dependent on local referendum. Referendum failed at election held in 1901; change did not take effect. (Utah Laws 1901, 4th sess., ch. 120, pp. 128-129; McPherson, 319-320)
18 March 1911
EMERY boundaries were redefined [no change]. (Utah Laws 1911, 9th sess., ch. 80, p. 115)
19 March 1913
JUAB exchanged with SANPETE. Boundary between JUAB and SANPETE was "indefinite and ambiguous to the extent that it has heretofore been impossible definitely to determine the exact direction of said boundary." This law was an attempt to settle the dispute [see 29 December 1916]. Boundary was also adjusted in T13S, R2E [not mapped]. (Utah Laws 1913, 10th sess., ch. 71, pp. 113-115; HRS Utah, Sanpete, 7-10)
4 January 1915
DUCHESNE created from WASATCH. Referendum held 13 July 1914; governor's proclamation took effect 4 January 1915. (Utah Laws 1913, 10th sess., ch. 28/pp. 35-38; Stout, 2: 361)
29 December 1916
The Utah State Supreme Court upheld the 19 March 1913 law that established part of the boundary between JUAB and SANPETE. ("Barton v. Sanpete Co.," in Utah Rpts., 49:188-195)
5 March 1917
DUCHESNE and SUMMIT gained from UINTAH. (Utah Laws 1917, 12th sess., chs. 34, 113/pp. 102-104, 336-337)
8 May 1917
WASHINGTON boundaries were clarified [no change]. (Utah Laws 1917, 12th sess., ch. 78, pp. 226-227)
IRON boundaries were clarified [no change]. (Utah Laws 1917, 12th sess., ch. 78, pp. 226-227)
RICH gained from SUMMIT [act overturned by Utah Supreme Court; see 19 January 1921]. (Utah Laws 1917, 12th sess., ch. 113, pp. 336-337)
7 January 1918
DAGGETT created from SUMMIT and UINTAH; voters approved the creation in July 1917 election. Creation took effect 7 January 1918. (HRS Utah, Daggett, 11-12; Dunham and Dunham, 319)
8 March 1919
MILLARD gained from JUAB; MILLARD and JUAB exchanged with SANPETE when boundaries were placed on public land survey lines. MILLARD boundary with JUAB west of the Sevier River was adjusted to run on public land survey lines [no mappable change]. (Utah Laws 1919, 13th sess., ch. 27, pp. 47-50)
1919
UINTAH gained from DAGGETT. (HRS Utah, Daggett, 12, 15; HRS Utah, Uintah, 14, 52)
19 January 1921
SUMMIT gained from RICH when Utah Supreme Court ruled the act of 8 May 1917 unconstitutional. ("Summit County v. Rich County," in Utah Rpts., 57:553-564)
10 March 1921
MILLARD exchanged with SEVIER. (Utah Laws 1921, 14th sess., ch. 33, pp. 104-106)
23 March 1931
SEVIER gained from PIUTE when boundary was placed on public land survey lines. (Utah Laws 1931, 19th sess., ch. 47, pp. 163-164)
11 May 1943
DAGGETT boundaries were clarified and placed on public land survey lines [no mappable change]. (Utah Laws 1943, 25th sess., ch. 28, pp. 28-29)
UINTAH boundaries were clarified and placed on public land survey lines [no mappable change]. (Utah Laws 1943, 25th sess., ch. 28, pp. 29-30)
28 May 1962
Utah Supreme Court ruled in favor of SAN JUAN and confirmed that the boundary between SAN JUAN and GRAND was 38 degrees, 30 minutes north latitude. GRAND contended the boundary was the south line of township 26 south [no change]. ("San Juan Co. v. Grand County," in Utah Rpts., 2d ser., vol. 13:242-246)
10 May 1977
DUCHESNE boundaries were clarified [no change]. (Utah Laws 1977, 42d leg., 1st sess., ch. 67, pp. 306-308)
UINTAH boundaries were clarified [no change]. (Utah Laws 1977, 42d leg., 1st sess., ch. 67, pp. 306-308)
1 January 2003
EMERY gained an area in the city of Green River from GRAND. (Utah State Bulletin, No. 19, 1 Oct. 2002, pp. 1-2; Utah State Bulletin, No. 2, 15 Jan. 2003, p. 2)