Green River County, Utah Genealogy

United States Utah  Green River County

Green River County, Utah Territory was 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, and the county is now extinct.

The only residents of this county on the 1856 Utah territorial census and Utah 1860 federal census were listed at Fort Bridger on the Oregon-California-Mormon Trail in present-day Wyoming. The Utah 1870 federal census does not have a Green River County.

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. This moved Green River County's western border to the present-day Wyoming border. However, the legislature also moved Green River County's southern border south of 39 1/2º taking much of Great Salt Lake, Utah, and Sanpete counties.

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.

On 17 January 1862 the legislature formed parts of Morgan and Wasatch counties from part of Green River County. On 16 January 1864 Utah erected Richland County (Rich after 1868) and expanded Summit County into the the western edge of Green River County.