Big Sky is a census-designated place (CDP) in Gallatin and Madison counties in southwestern Montana. As of the 2010 census it had a population of 2,308. It is 45 miles (72 km) southwest of Bozeman. This unincorporated community straddles both counties, is not considered a town, and does not have a town government. The primary industry of the area is tourism.
Big Sky is located at 45°16′12″N 111°17′59″W (45.269940, -111.299725), approximately midway between West Yellowstone and Bozeman on U.S. Highway 191 and just 15 miles (24 km) from the northwestern border of Yellowstone National Park.
The "Meadow" area of Big Sky lies in an alpine valley formed during the Cretaceous period. Initially called the "Gallatin Canyon Basin", the Meadow is braided with small rivers that channel mountain snow run-off. Fishing is permitted on all of these Gallatin feeders. Two ponds are found on the Middle Fork of the Gallatin River that bisects the Meadow, and fishing there is permitted for those 16 and younger. Since 1993, an innovative sewer system has protected the water in the area from sewage discharge.