Tooele County, Utah Dugway Proving Ground in Tooele County. The county's western portion is home to the Bonneville Salt Flats, traversed by Interstate 80 and the Wendover Cut-off, the former routing of the Victory Highway. According to the U.S. Census Bureau, the county has a total area of , of which is land and (4.7%) is water. Covering vast amounts of the Great Salt Lake desert west of Salt Lake Valley, Tooele County is the second largest county in Utah and among the driest. As of the census of 2000, there were 40,735 people, 12,677 households, and 10,128 families residing in the county.
Salt Lake County, Utah Salt Lake County, Utah Salt Lake County is a county located in the U.S. state of Utah. As of the 2010 census, the population was 1,029,655, making it the most populous county in Utah. Its county seat and largest city is Salt Lake City, the state capital. The county was created in 1850. Salt Lake County occupies the Salt Lake Valley, as well as parts of the surrounding mountains, the Oquirrh Mountains to the west and the Wasatch Range to the east (essentially the entire Jordan River watershed north of the Traverse Mountains). In addition, the northwestern section of the