Gray Reef

NORTH PLATE RIVER· Natrona, Wyoming· Built 1961· Earth· 38 ft tall
Low Hazard Irrigation Federal Government

Key Takeaway

Gray Reef is classified as low hazard in Wyoming. It was completed in 1961 and is 65 years old. Its primary use is irrigation.

Physical Details

Dam Height 38 ft (taller than 84.6% in WY)
Dam Length650 ft
Dam TypeEarth
Max Storage1.8K acre-ft
Normal Storage1.8K acre-ft
Surface Area182 acres
Drainage Area11,000 sq mi
Max Discharge20,700 cfs
Year Completed1961 (65 years old)
NID IDWY01292

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
State Regulated: Yes
Regulatory Agency: SEO

Ownership

RECLAMATION

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Gray Reef?

Gray Reef is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Gray Reef?

Gray Reef is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Gray Reef built?

Gray Reef was completed in 1961, making it 65 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Gray Reef?

Gray Reef serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Gray Reef?

Gray Reef has a dam height of 38 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.