Waters of the North Platte River must pass the Seminoe and Kortes Dams before entering the reservoir at Pathfinder Dam, which impounds the flow from Sweetwater River. Pathfinder Reservoir has a storage capacity of 1,016,000 acre-feet and holds much of the North Platte Project water. During the nonirrigation season, a small amount of water is released to satisfy other water rights, enhance fish and wildlife, and operate power plants downstream. During the irrigation season, water is released as required, including water flowing from Seminoe Reservoir to be diverted at Alcova Dam for irrigation on the Kendrick Project.
Pathfinder Dam is one of the first constructed by the Reclamation Service. The dam is in a granite canyon on the North Platte River about 3 miles below its junction with the Sweetwater River and about 47 miles southwest of Casper, Wyoming. It is made of granite quarried from nearby hills, and is faced with large rectangular blocks laid in horizontal courses. It is an arch dam with a gravity-type section, and has a structural height of 214 feet.
Pathfinder Dike fills a depression in the natural ground surface about 0.25 miles south of the dam. It is an earth-fill structure, 38 feet high, with a concrete corewall.
Foundation: Coarse-grained, massive granite; local vertical crush zone at left abutment; some flat mud seams in canyon floor