The Bighorn Basin is a plateau region and intermontane basin, approximately 100 miles (160 km) wide, in north-central Wyoming in the United States. It is bounded by the Absaroka Range on the west, the Pryor Mountains on the north, the Bighorn Mountains on the east, and the Owl Creek Mountains and Bridger Mountains on the south. It is drained to the north by tributaries of the Bighorn River, which enters the basin from the south, through a gap between the Owl Creek and Bridger Mountains, as the Wind River, and becomes the Bighorn as it enters the basin. The region is semi-arid, receiving only 6–10 in (15–25 cm) of rain annually.

Wyoming is a landlocked state in the Mountain West subregion of the Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the south. With a population of 576,851 in 2020, Wyoming is the least populous state despite being the 10th largest by area, with the second-lowest population density after Alaska. The state capital and most populous city is Cheyenne, which had a population of 65,132 in 2020.