J & J

POISON SPIDER CR· Natrona, Wyoming· Built 1942· Earth· 25 ft tall
Low Hazard Irrigation Private

Key Takeaway

J & J is classified as low hazard in Wyoming. It was completed in 1942 and is 84 years old. Its primary use is irrigation.

Physical Details

Dam Height 25 ft (taller than 39.5% in WY)
Dam Length918 ft
Dam TypeEarth
Max Storage2.4K acre-ft
Normal Storage1.4K acre-ft
Surface Area173 acres
Drainage Area0 sq mi
Max Discharge0 cfs
Year Completed1942 (84 years old)
NID IDWY00239

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: June 21, 2023
State Regulated: Yes
Regulatory Agency: SEO

Ownership

WILD HORSE BASIN RANCH

Private

Frequently Asked Questions

What is the hazard classification of J & J?

J & J 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 & J?

J & J is owned by WILD HORSE BASIN RANCH (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was J & J built?

J & J was completed in 1942, making it 84 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 J & J?

J & J 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 & J?

J & J 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 J & J last inspected?

J & J was last inspected on June 21, 2023. 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.