Pathfinder National Wildlife Refuge (NWR) was established in 1928 by Executive Order 4860 which reserved public lands on Pathfinder Reservoir as a refuge and breeding ground for native birds. The Refuge overlays portions of the Bureau of Reclamations Pathfinder Reservoir. The Refuge consists of four small units totaling 16,807 acres. They are Sweetwater Arm, Goose Bay, DeWeese Creek, and Sage Creek. The Refuge is an important waterfowl unit in the western edge of the Central Flyway. Upland portions of the Refuge provide habitat for pronghorn, mule deer, rabbits, and sage grouse. The Refuge is not staffed and is a satellite of Arapaho NWR.

The Refuge wetlands provide feeding and resting areas for waterfowl during their annual migrations. Since the reservoir itself fluctuates as much as 50 feet per year, it is difficult to provide cover for waterfowl nesting. Other waterbirds such as willets, American avocets, Wilson's phalaropes, American coots, and great blue herons also use the wetland areas. Upland portions of the Refuge are sagebrush / grassland habitats; they provide habitat for pronghorn, mule deer, rabbits, and sage grouse.