Dull Knife

NORTH FORK POWDER RIVER· Johnson, Wyoming· Built 1966· Earth· 80 ft tall
High Hazard Irrigation Private

Key Takeaway

Dull Knife is classified as high hazard in Wyoming. It was completed in 1966 and is 60 years old. Its primary use is irrigation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 80 ft (taller than 97.2% in WY)
Dam Length570 ft
Dam TypeEarth
Max Storage5.0K acre-ft
Normal Storage4.3K acre-ft
Surface Area130 acres
Drainage Area26 sq mi
Max Discharge2,800 cfs
Year Completed1966 (60 years old)
Year Modified2018
NID IDWY00557

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes
Last Inspection: July 13, 2022
State Regulated: Yes
Regulatory Agency: SEO

Ownership

NORTH FORK POWDER RIVER WATER USERS ASSN

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Dull Knife?

Dull Knife is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Dull Knife?

Dull Knife is owned by NORTH FORK POWDER RIVER WATER USERS ASSN (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Dull Knife built?

Dull Knife was completed in 1966, making it 60 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 Dull Knife?

Dull Knife 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 Dull Knife?

Dull Knife has a dam height of 80 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.

When was Dull Knife last inspected?

Dull Knife was last inspected on July 13, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

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.