Operating Hours & Seasons - Lake Roosevelt National Recreation Area (U.S. National Park Service) Lake Roosevelt National Recreation Area is open for recreational use 24 hours per day, 365 days per year. Variable lake levels can lead to the closure of boat launches and the loss of water pressure in some campgrounds. During an average year, the Bureau of Reclamation brings the lake near full pool from mid-June until Labor Day. Check the current lake level and refer to the boat launch elevation guide before you visit, especially during the fall, winter, or spring.