Lake Estes, a feature of the Colorado-Big Thompson Project, is formed by Olympus Dam constructed across the Big Thompson River. The afterbay storage in Lake Estes and the forebay storage in Marys Lake enable the Estes powerplant to meet daily variations in energy demand. Recreation facilities include a nine-hole golf course, five picnic and associated day-use areas, and a marina. Good access to recreation areas. The reservoir has approximately 185 water surface acres, 213 land acres and 4 milesof shoreline. Power boating is limited, but available. Sailing opportunities. Fish species available are largely rainbow trout. Facilities are closed in winter due to ice and snow.