Ouachita Mountains, Oklahoma, USA
The Ouachita Mountains are a mountain range located in southeastern Oklahoma (visible here) and west central Arkansas.
Above the mountain range, just left of center, are two large lakes: Eufaula Lake and the Robert S. Kerr Reservoir. The Red River runs just south of the range, providing the border line between Oklahoma and Texas.
Eufaula Lake (left) is a reservoir in Oklahoma, and the largest lake in the state. It is located on the Canadian River, 27 mi (43 km) upstream from its confluence with the Arkansas River and near the town of Eufaula.
Construction of the 975 metres long dam wall began in 1956 and was completed in 1964. The dam holds back a lake area of over 412 square kilometres. A hydroelectric powerstation provides power from the lake waters.
Robert S. Kerr Reservoir (right) is also located in Oklahoma, but is on the Arkansas River. The reservoir is impounded by Robert S. Kerr Lock and Dam at river mile 336.2 (km 541.1) on the Arkansas River, just a few miles below its confluence with the Canadian River.