In 1906, the Water Supply and Storage Company proposed constructing a dam across La Poudre Pass Creek (also known as Long Draw Creek). The resulting reservoir would prevent the overburdening of the Poudre River and permit more efficient operation of the Grand River Ditch. However, much of the land at the site was part of Rocky Mountain National Park, which an act of Congress had created in 1915. In June 1924, an Act of Congress approved the transfer of these lands from the National Park Service to the U. S. Forest Service.

In 1927, construction began on the dam, and Long Draw Reservoir was completed in 1930 with a storage capacity of 4,000 acre feet. Significant in the construction was the use of mechanization. The contractor, Hamilton Gleason, employed gasoline-powered steam shovels for the construction process. In 1974, Water Supply and Storage Company enlarged the reservoir to an 11,000 acre-foot capacity, giving the Grand River Ditch-Long Draw Reservoir system a total capacity of 30,000 acre feet. Enlargement included construction of USFS-managed recreational facilities, including campground, picnic areas, restrooms, and trailhead for Big South area.

Citations:

-Stanley R. Case, The Poudre: A Photo History. Bellvue, CO: Stanley R. Case, 1995. pp. 234-235.

-Howard Ensign Evans and Mary Alice Evans. Cache La Poudre: The Natural History of a Rocky Mountain River. Niwot, CO: University Press of Colorado, 1991. pp. 46-47.