Grimes Dam

GRIMES CREEK· Custer, Montana· Built 1950· Earth· 16 ft tall
Low Hazard Irrigation Private

Key Takeaway

Grimes Dam is classified as low hazard in Montana. It was completed in 1950 and is 76 years old. Its primary use is irrigation.

Physical Details

Dam Height 16 ft (taller than 31.7% in MT)
Dam Length625 ft
Dam TypeEarth
Max Storage188 acre-ft
Normal Storage79 acre-ft
Year Completed1950 (76 years old)
NID IDMT01816

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: DNRC

Ownership

B 6 RANCH INC

Private

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Lazy S #2

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Fillafer #1

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Pfaff Irrigation

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Hamlick Reservoir

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Cap Rock #1

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Frequently Asked Questions

What is the hazard classification of Grimes Dam?

Grimes Dam 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 Grimes Dam?

Grimes Dam is owned by B 6 RANCH INC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Grimes Dam built?

Grimes Dam was completed in 1950, making it 76 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 Grimes Dam?

Grimes Dam 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 Grimes Dam?

Grimes Dam has a dam height of 16 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.