Mcninch No. 1

BEAVER CREEK OFFSTREAM· Sublette, Wyoming· Built 1947· Earth· 33 ft tall
Low Hazard Irrigation Private

Key Takeaway

Mcninch No. 1 is classified as low hazard in Wyoming. It was completed in 1947 and is 79 years old. Its primary use is irrigation.

Physical Details

Dam Height 33 ft (taller than 75.3% in WY)
Dam Length1,150 ft
Dam TypeEarth
Max Storage1.6K acre-ft
Normal Storage1.1K acre-ft
Surface Area107 acres
Drainage Area2 sq mi
Max Discharge21 cfs
Year Completed1947 (79 years old)
NID IDWY01273

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
Last Inspection: August 12, 2020
State Regulated: Yes
Regulatory Agency: SEO

Ownership

RANDAL MCNINCH & SHAWNA COWDEN

Private

Nearby Dams

Mcninch No. 2

Sublette, WY

Low Hazard 27 ft

Sixty Seven

Sublette, WY

High Hazard 32 ft

First Enl. Joe Budd

Sublette, WY

Low Hazard 15 ft

Sphaeralcea

Sublette, WY

Low Hazard 28 ft

Frequently Asked Questions

What is the hazard classification of Mcninch No. 1?

Mcninch No. 1 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 Mcninch No. 1?

Mcninch No. 1 is owned by RANDAL MCNINCH & SHAWNA COWDEN (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mcninch No. 1 built?

Mcninch No. 1 was completed in 1947, making it 79 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 Mcninch No. 1?

Mcninch No. 1 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 Mcninch No. 1?

Mcninch No. 1 has a dam height of 33 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 Mcninch No. 1 last inspected?

Mcninch No. 1 was last inspected on August 12, 2020. 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.