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.

The Shoshone Project is an irrigation project in the U.S. state of Wyoming. The project provides irrigation for approximately 107,000 acres (430 km2) of crops in the Big Horn Basin, fulfilling the vision of local resident and developer Buffalo Bill Cody, who hoped to make the semi-arid basin into agricultural land. Buffalo Bill Dam on the Shoshone River impounds water for the project in Buffalo Bill Reservoir. In addition to its role in irrigation, the project provides flood control on the Shoshone and generates power, using the 350-foot (110 m) height of Buffalo Bill Dam, once a world record, and the considerable fall of the river through Shoshone Canyon to generate hydroelectric power. Chief crops in the Big Horn Basin are sugar beets, alfalfa, barley, oats, corn and beans.