Shell Creek
Shell Creek is an earth dam located in Big Horn County, Wyoming, built in 1957. It carries a High hazard potential classification.
About Shell Creek
The primary purpose of Shell Creek is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Shell Valley Reservoir Company, Inc (private). It impounds the Shell Creek near Shell.
The dam stands 50 feet tall and stretches 400 feet across, creates a reservoir covering 98 acres, has a maximum storage capacity of 2,680 acre-feet, and collects water from a drainage area of 24 square miles. Completed in 1957, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 10/01/2025.
At 50 feet, this dam is taller than 93% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wyoming dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Wyoming |
| County | Big Horn |
| Nearest City | Shell |
| River/Stream | Shell Creek |
| Coordinates | 44.51660, -107.41390 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Height | 40 ft |
| Dam Length | 400 ft |
| Year Completed | 1957 (69 years old) |
Storage & Hydraulics
| NID Storage | 2,680 acre-ft |
| Max Storage | 2,680 acre-ft |
| Normal Storage | 1,950 acre-ft |
| Surface Area | 98 acres |
| Drainage Area | 24 sq mi |
| Max Discharge | 1,800 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | SHELL VALLEY RESERVOIR COMPANY, INC |
| Owner Type | Private |
| Hazard Classification | High |
| Last Inspection | 10/01/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WY01100 |
| Federal ID | WY01100 |
| More Info | State Dam Safety Program |