Grand Lake is Colorado’s largest and deepest natural water body. The lake’s beauty and proximity to the west entrance of Rocky Mountain National Park draw thousands of visitors annually.
Located between Shadow Mountain Reservoir and the Alva B. Adams Tunnel’s West Portal, Grand Lake plays a key role in the Colorado-Big Thompson (C-BT) Project. It is the last water body C-BT Project water flows through before entering the Adams Tunnel on its way to the East Slope and Northeastern Colorado. C-BT Project operations criteria minimize fluctuations in Grand Lake’s water level to less than 1 vertical foot.
Grand Lake has a capacity of 68,600 acre-feet, 515 surface acres, 4.5 miles of shoreline and a maximum depth of 265 feet.