New Fork Lake
New Fork Lake is an earth dam located in Sublette County, Wyoming, built in 1925. It carries a High hazard potential classification.
About New Fork Lake
The primary purpose of New Fork Lake is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by New Fork Lake Irrigation District (private). It impounds the West Fork Of New Fork River near Pinedale.
The dam stands 37 feet tall and stretches 250 feet across, creates a reservoir covering 1,416 acres, has a maximum storage capacity of 25,700 acre-feet, and collects water from a drainage area of 31 square miles. Completed in 1925, the structure is over a century 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 06/24/2025.
At 37 feet, this dam is taller than 84% 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 | Sublette |
| Nearest City | Pinedale |
| River/Stream | West Fork Of New Fork River |
| Coordinates | 43.08690, -109.96880 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 37 ft |
| Dam Height | 37 ft |
| Dam Length | 250 ft |
| Year Completed | 1925 (101 years old) |
Storage & Hydraulics
| NID Storage | 25,700 acre-ft |
| Max Storage | 25,700 acre-ft |
| Normal Storage | 20,340 acre-ft |
| Surface Area | 1,416 acres |
| Drainage Area | 31 sq mi |
| Max Discharge | 2,260 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | NEW FORK LAKE IRRIGATION DISTRICT |
| Owner Type | Private |
| Hazard Classification | High |
| Last Inspection | 06/24/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WY01232 |
| Federal ID | WY01232 |
| More Info | State Dam Safety Program |