Gross Reservoir

Named for Denver Water former Chief Engineer Dwight D. Gross, the reservoir was completed in 1954. It serves as a combination storage and regulating facility for water that flows under the Continental Divide through the Moffat Tunnel. Standing 340 feet above the South Boulder Creek streambed, Gross Dam contains some 627,559 cubic yards of concrete. Gross Reservoir has a surface area of 440 acres and 10.9 miles of shoreline. Seasonal Information Open year round. Boating season starts on the Friday of Memorial Day weekend and ends Sept. 30. Kokanee snagging runs from Sept. 1 – Jan. 31. West site U.S. Forest Service closes from late fall to early spring: check with the U.S. Forest Service Boulder district for specific closure dates.