Green River County, Utah Genealogy
Green River County, Utah Territory was an extinct county created 3 March 1852   in the northeast corner of Utah Territory on land that eventually became parts of Utah, Wyoming, and Colorado. The remnants of Green River County in Utah Territory were finally dissolved on 16 February 1872.
In 1852 the original Green River County was bounded on the north by Utah Territory's northern border at 42º, on the east by Utah Territory's eastern border at the crest of the Rocky Mountains, on the south by Great Salt Lake County, and on the east by Weber and Davis counties.
On 13 January 1854 the Utah Territoral legislature created Summit County from part of Green River County. On 5 January 1856 the legislature carved parts of Malad, Box Elder, and Cache Counties out of part of Green River County.
In 1861 the U.S. Congress began carving pieces off of Utah Territory to give to other territories. Parts of Utah Territory were given to form parts of Colorado, Nebraska (later Wyoming), and all of the original Nevada Territory. Two of these giveaways directly affected Green River County. Utah Territory south of 41º and east of 109º was given to Colorado Territory which included about half of Green River County. The Green River County land north of 41º and east of 110º was given to Nebraska Territory (later Wyoming) leaving Green River County less than a tenth of its previous size.
- Utah Territory Legislative Assembly, Acts, resolutions, and memorials, passed by the first annual, and special sessions, of the Legislative Assembly, of the Territory of Utah, begun and held at Great Salt Lake City, on the 22nd day of September, A.D., 1851 (1852) (G.S.L. City, U.T.: Legislative Assembly, 1852), 162. Internet Archive edition.
- Handybook for Genealogists: United States of America, 10th ed. (Draper, Utah: Everton Pub., 2002), 686. WorldCat entry. FHL Book 973 D274 2002.
- "Chart of County Formation in Utah" in Division of Archives and Records Service at http://archives.utah.gov/research/guides/county-formation.htm (accessed 11 August 2011).
- Deon C. Greer, Atlas of Utah (Ogden, Utah: Desert State College, 1981), 161-64. WorldCat entry. FHL Q Book 979.2 E7a.