Twin No. 1

BETZ DRAW· Johnson, Wyoming· Built 1957· Earth· 47 ft tall
Low Hazard Fire Protection Stock Or Small Fish Pond Private

Key Takeaway

Twin No. 1 is classified as low hazard in Wyoming. It was completed in 1957 and is 69 years old. Its primary use is fire protection.

Physical Details

Dam Height 47 ft (taller than 92.6% in WY)
Dam Length225 ft
Dam TypeEarth
Max Storage60 acre-ft
Normal Storage39 acre-ft
Surface Area3 acres
Drainage Area0 sq mi
Max Discharge0 cfs
Year Completed1957 (69 years old)
NID IDWY00497

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: April 21, 2022
State Regulated: Yes
Regulatory Agency: SEO

Ownership

BETZ RANCH LLC

Private

Nearby Dams

Henry

Johnson, WY

Low Hazard 30 ft

Green Cabin No. 3

Sheridan, WY

Low Hazard 27 ft

Rattlesnake No. 1

Johnson, WY

Low Hazard 30 ft

Fowler

Johnson, WY

Low Hazard 21 ft

Ben

Johnson, WY

Low Hazard 29 ft

Green Cabin

Sheridan, WY

Low Hazard 30 ft

Big Donaldson

Johnson, WY

Low Hazard 22 ft

Mary Stock

Johnson, WY

Low Hazard 38 ft

Frequently Asked Questions

What is the hazard classification of Twin No. 1?

Twin 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 Twin No. 1?

Twin No. 1 is owned by BETZ RANCH LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Twin No. 1 built?

Twin No. 1 was completed in 1957, making it 69 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 Twin No. 1?

Twin No. 1 serves the following purposes: Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Twin No. 1?

Twin No. 1 has a dam height of 47 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 Twin No. 1 last inspected?

Twin No. 1 was last inspected on April 21, 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.