Mountain Lake

Blue Earth River-TR· Cottonwood, Minnesota· Built 1960· Other· 10 ft tall
Significant Hazard Recreation State Government

Key Takeaway

Mountain Lake is classified as significant hazard in Minnesota. It was completed in 1960 and is 66 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 10 ft (taller than 30.9% in MN)
Dam Length25 ft
Dam TypeOther
Max Storage1.8K acre-ft
Normal Storage1.1K acre-ft
Surface Area230 acres
Drainage Area10 sq mi
Max Discharge400 cfs
Year Completed1960 (66 years old)
Year Modified2007
NID IDMN00165

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: June 28, 2022
State Regulated: Yes
Regulatory Agency: MNDNR EWR

Ownership

MNDNR

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mountain Lake?

Mountain 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 Mountain Lake?

Mountain Lake is owned by MNDNR (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mountain Lake built?

Mountain Lake was completed in 1960, making it 66 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 Mountain Lake?

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

How tall is Mountain Lake?

Mountain Lake has a dam height of 10 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 Mountain Lake last inspected?

Mountain Lake was last inspected on June 28, 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.