Rob Roy
Rob Roy is an earth dam located in Albany County, Wyoming, built in 1986. It carries a High hazard potential classification and has a fair condition assessment.
About Rob Roy
The primary purpose of Rob Roy is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Cheyenne Board Of Public Utilities (local government). It impounds the Douglas Creek near Keystone.
The dam stands 150 feet tall and stretches 1,095 feet across, creates a reservoir covering 801 acres, has a maximum storage capacity of 42,264 acre-feet, and collects water from a drainage area of 20 square miles. Completed in 1986, the structure is 40 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. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 10/08/2025.
At 150 feet, this dam is taller than 99% of all dams in the United States.
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 | Albany |
| Nearest City | Keystone |
| River/Stream | Douglas Creek |
| Coordinates | 41.19691, -106.26562 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 150 ft |
| Dam Height | 140 ft |
| Dam Length | 1,095 ft |
| Year Completed | 1986 (40 years old) |
Storage & Hydraulics
| NID Storage | 42,264 acre-ft |
| Max Storage | 42,264 acre-ft |
| Normal Storage | 35,434 acre-ft |
| Surface Area | 801 acres |
| Drainage Area | 20 sq mi |
| Max Discharge | 4,500 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | CHEYENNE BOARD OF PUBLIC UTILITIES |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 10/08/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WY00084 |
| Federal ID | WY00084 |
| More Info | State Dam Safety Program |