Ralston #1 is a privately owned earth dam located in Garfield County, Colorado, near the city of Glenwood Springs. Built in 1904 for irrigation purposes, the dam stands at a height of 20 feet and has a storage capacity of 70 acre-feet. It is situated on West Coulter Creek-TR and is regulated by the Colorado Department of Water Resources.

Despite its low hazard potential, the dam is currently in unsatisfactory condition, as indicated by a recent inspection in June 2020. The spillway type is uncontrolled, with a width of 5 feet. The dam has one slide (sluice gate) outlet gate and a moderate risk assessment rating of 3. While there have been no major modifications to the structure in recent years, regular inspections are conducted every 6 years to assess its safety and integrity.

Water resource and climate enthusiasts interested in the historical significance and engineering aspects of Ralston #1 will find this dam a fascinating example of early irrigation infrastructure in the region. With its stone core and rock and soil foundations, the dam serves multiple purposes including fire protection, stock watering, and small fish pond management. Its location in a picturesque setting near Glenwood Springs adds to its appeal for those interested in exploring the intersection of water management and environmental conservation in Colorado.