Foss State Park is located in west central Oklahoma in Custer County
on the southern end of Foss Lake
. It is 11 miles west-northwest of Clinton
on SR 73.
The 1750-acre park features the 8,800-acre lake, 120 campsites with assigned campground, hiking and biking trails, an equestrian trail, a swimming beach, boating and paddleboating as well as water skiing and fishing. The impound is contained by the world's largest earthen dam at a length of 3 miles and is fed by the Washita River.
Boat rentals are available at the marina, dining at the restaurant, and gifts at the gift shop.