J.L. Big Reservoir

SAGE CREEK· Glacier, Montana· Earth· 24 ft tall
Low Hazard Irrigation Private

Key Takeaway

J.L. Big Reservoir is classified as low hazard in Montana. Its primary use is irrigation.

Physical Details

Dam Height 24 ft (taller than 67.5% in MT)
Dam TypeEarth
Max Storage342 acre-ft
Normal Storage342 acre-ft
Surface Area59 acres
NID IDMT03849

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

DUNCAN RANCH COMPANY

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of J.L. Big Reservoir?

J.L. Big Reservoir 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 J.L. Big Reservoir?

J.L. Big Reservoir is owned by DUNCAN RANCH COMPANY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of J.L. Big Reservoir?

J.L. Big Reservoir 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 J.L. Big Reservoir?

J.L. Big Reservoir has a dam height of 24 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.