Rock
Rock is an earth dam located in Fremont County, Wyoming, built in 1978. It carries a Low hazard potential classification and has a fair condition assessment.
About Rock
The primary purpose of Rock is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Kennecott Uranium Company & Wyoming Coal Resources Company (private). It impounds the Off Channel Trib Antelope Cr near Hwy. 287/789.
The dam stands 30 feet tall and stretches 550 feet across, creates a reservoir covering 4 acres, and has a maximum storage capacity of 48 acre-feet. Completed in 1978, the structure is 48 years 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 05/16/2023.
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Location
| State | Wyoming |
| County | Fremont |
| Nearest City | Hwy. 287/789 |
| River/Stream | Off Channel Trib Antelope Cr |
| Coordinates | 42.33417, -107.79250 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 30 ft |
| Dam Height | 30 ft |
| Dam Length | 550 ft |
| Year Completed | 1978 (48 years old) |
Storage & Hydraulics
| NID Storage | 48 acre-ft |
| Max Storage | 48 acre-ft |
| Normal Storage | 28 acre-ft |
| Surface Area | 4 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | KENNECOTT URANIUM COMPANY & WYOMING COAL RESOURCES COMPANY |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 05/16/2023 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY01513 |
| Federal ID | WY01513 |
| More Info | State Dam Safety Program |