| 8,800 acres (3,600 ha)|
| 436,812 acre·ft (538.800 hm)|
United States Bureau of Reclamation
Foss Reservoir, also known as Foss Lake, lies in Custer County, Oklahoma on the Washita River, about 15 miles (24 km) west of Clinton, Oklahoma. The reservoir was constructed during 1958–1961 by the U. S. Bureau of Reclamation. The project was known originally as the Washita Basin Project. The lake and dam were named for the community of Foss, Oklahoma, about 6 miles (9.7 km) south of the site. The primary purposes are to regulate flow of the river and to provide water for the cities of Bessie, Clinton, Cordell and Hobart. It is western Oklahoma's largest lake and lies entirely within Foss State Park.
The reservoir has a surface area of 8,800 acres (3,600 ha) and a shoreline of 63 miles (101 km). The capacity of the reservoir is 436,812 acre-feet.
Dam construction began in October, 1958. The dam is 142 feet (43 m) high, 38 feet (12 m) wide (at the crest) and 18,130 feet (5,530 m) long.
The water quality in Lake Foss is extremely hard. The Bureau of Reclamation built one of the first electrodialysis plants in the United States to process the water before it is delivered to users. The Oklahoma Department of Environmental Quality constructed a new, updated plant to replace the original in 2002.
Water is transported from the dam to consumers via three pumping stations and 50.8 miles (81.8 km) of aqueducts.
Foss Reservoir Wikipedia
In September 2013, two cars believed to have been submerged since 1969, and 1970 were found at the bottom of Foss Reservoir by Oklahoma Highway Patrol officers testing new sonar equipment. The cars, a 1952 Chevrolet and a blue 1969 Chevrolet Camaro, each contained three sets of skeletal human remains. They were suspected to be linked to two separate, long-open cold cases from the late 1960s, in the case of the older car, and 1970, in the case of the Camaro. The cases were solved in October 2014 when it was announced that both cases were solved, with the 1969 case involving three adults and the 1970 case involving three teenagers. Both cases were ruled accidental.