Lewis
Lewis is an earth dam located in Laramie County, Wyoming, built in 1908. It carries a Low hazard potential classification and has a fair condition assessment.
About Lewis
The primary purpose of Lewis is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Nimmo Ranch Company (private). It impounds the Horse Creek near Morrill, Neb.
The dam stands 26 feet tall and stretches 1,100 feet across, creates a reservoir covering 14 acres, and has a maximum storage capacity of 244 acre-feet. Completed in 1908, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 09/11/2025.
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Location
| State | Wyoming |
| County | Laramie |
| Nearest City | Morrill, Neb |
| River/Stream | Horse Creek |
| Coordinates | 41.46917, -104.84750 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 1,100 ft |
| Year Completed | 1908 (118 years old) |
Storage & Hydraulics
| NID Storage | 244 acre-ft |
| Max Storage | 244 acre-ft |
| Normal Storage | 170 acre-ft |
| Surface Area | 14 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | NIMMO RANCH COMPANY |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 09/11/2025 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY00095 |
| Federal ID | WY00095 |
| More Info | State Dam Safety Program |