Greybull Valley (1st Enl.)

About Greybull Valley (1st Enl.)

The primary purpose of Greybull Valley (1st Enl.) is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Greybull Valley Irrigation District (private). It impounds the Red Clay Draw near Unnamed Ranch.

The dam stands 207 feet tall and stretches 1,798 feet across, creates a reservoir covering 691 acres, has a maximum storage capacity of 53,200 acre-feet, and collects water from a drainage area of 11 square miles. Completed in 2000, the structure is 26 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 05/14/2024.

At 207 feet, this dam is taller than 99% of all dams in the United States.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wyoming dam safety program can provide more specific information about emergency planning for this structure.

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