First ratified in 1922, the Colorado River Compact agreed to divide the water of the “American Nile” between the seven states of the Colorado Basin. The water was divided between the upper and lower basins and establishes the cornerstone of the Law of the River. The Compact also provided that the Upper Basin states could not allow the flow of the river at Lee Ferry, Arizona to fall below 75 MAF for any period of ten consecutive years. In 1944, a treaty was signed to supply Mexico with a 1.5 MAF of water annually, thus obligating 16.5 MAF of Colorado River annually. Between 1928 and 1956 several new Acts and agreements governed the water development of the lower basin as California’s water needs grew with its steadily increasing population.

The Colorado River Storage Project (CRSP) Act was passed in 1956 providing a comprehensive upper basin-wide water development plan with the primary purpose of ensuring the upper basin’s water rights and meeting the 1922 Compact’s delivery requirement to the lower basin. The original CRSP proposal included the Echo Park and Split Mountain Dam projects, which would have backed Green River water up into Dinosaur National Mounument. As the symbolic birth of the modern Environmental Movement , public opposition organized to demand the omission of the “Dinosaur Dams”.

The Sierra Club fought and stopped a proposal to dam the Green River in Dinosaur National Monument as part of the Colorado River Storage Project in the early 1950’s. The alternative to the Echo Park and Split Mountain Dams accepted by the Sierra Club was a 710 foot dam in Glen Canyon on the Colorado River. After the passage of the CRSP in 1956, David Brower, then Executive Director of the Sierra Club, said Glen Canyon Dam would become “America’s most regretted environmental mistake.” A strong fight was mounted against the construction of the dam, but it was too late. The damming of Glen Canyon became a catalyst for the modern environmental movement.