Little Lake

TR-WRANGLE CREEK· Missoula, Montana· Built 1912· Rockfill· 25 ft tall
Significant Hazard Water Supply Local Government

Key Takeaway

Little Lake is classified as significant hazard in Montana. It was completed in 1912 and is 114 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 25 ft (taller than 70.3% in MT)
Dam Length300 ft
Dam TypeRockfill
Max Storage298 acre-ft
Normal Storage125 acre-ft
Surface Area32 acres
Drainage Area1 sq mi
Max Discharge500 cfs
Year Completed1912 (114 years old)
NID IDMT03673

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: No
Last Inspection: August 1, 2017
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

CITY OF MISSOULA

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Little Lake?

Little Lake is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Little Lake?

Little Lake is owned by CITY OF MISSOULA (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Little Lake built?

Little Lake was completed in 1912, making it 114 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 Little Lake?

Little Lake serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Little Lake?

Little Lake has a dam height of 25 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 Little Lake last inspected?

Little Lake was last inspected on August 1, 2017. 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.