Rifle Gap Dam is constructed on Rifle Creek about 5.5 miles north of Rifle, Colorado, at a point where the creek cuts through the Grand Hogback. The dam is a zoned earthfill structure with a height of 157 feet, a crest length of 1,450 feet, and a volume of 1,768,000 cubic yards of material. The spillway consists of a short approach channel, concrete inlet walls, concrete crest structure, and concrete chute and stilling basin. Early History Most early settlers were miners and prospectors who turned to irrigated agriculture after being unsuccessful in mining attempts. When the railroad failed a short time later, the families remained and turned to farming in the vicinity.
Agriculture is the region's basic industry.
Several thousand acres of rangeland and National Forest reserves surround the cultivated areas and are used for summer grazing. Investigations of the Silt Project by the Bureau of Reclamation began in 1936. A report on the Colorado River dated March 1946 briefly described a project plan that was similar to the present plan. The plan was described in greater detail in a January 1951 report on the Silt Project, which served as a supplement to the 1950 report on the Colorado River Storage Project and participating projects. The 1950 report was amended in 1953 and was the basis for authorization of the Silt Project.