Agnes Lake

AGNES CREEK· Beaverhead, Montana· Built 1928· Earth· 13 ft tall
High Hazard Irrigation Private

Key Takeaway

Agnes Lake is classified as high hazard in Montana. It was completed in 1928 and is 98 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 13 ft (taller than 14.7% in MT)
Dam Length174 ft
Dam TypeEarth
Max Storage1.9K acre-ft
Normal Storage790 acre-ft
Surface Area99 acres
Drainage Area3 sq mi
Max Discharge560 cfs
Year Completed1928 (98 years old)
NID IDMT00817

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: No
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

BURK RANCHES INC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Agnes Lake?

Agnes Lake 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 Agnes Lake?

Agnes Lake is owned by BURK RANCHES INC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Agnes Lake built?

Agnes Lake was completed in 1928, making it 98 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 Agnes Lake?

Agnes Lake 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 Agnes Lake?

Agnes Lake has a dam height of 13 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.