Nestled at the foot of the Rocky Mountains near Granby, Eleven Mile Reservoir is a 2,000‑acre body of water created by the Eleven Mile Dam on the Arkansas River. It serves multiple purposes: storing water for downstream irrigation, generating hydroelectric power, and offering year‑round recreation such as boating, fishing, and hiking along its shoreline. The lake’s high‑altitude setting provides crisp air, dramatic peaks, and abundant wildlife, making it a magnet for outdoor enthusiasts looking for a remote Colorado experience.
The reservoir is managed by the U.S. Bureau of Reclamation, which balances water releases for agriculture with maintaining lake levels for recreation. Seasonal inflows from snowmelt can raise the surface dramatically in spring, while late summer often brings lower levels that expose shorelines and affect boat launch sites. Because the water is part of a larger river system, water‑quality monitoring is ongoing, and occasional algae growth can occur, especially during warm, stagnant periods.