The Tri-Valley District is located in the southwest and southcentral portions of Nebraska. It includes the counties of:
- Adams
- Buffalo
- Chase
- Dawson
- Dundy
- Franklin
- Frontier
- Furnas
- Gosper
- Hall
- Hamilton
- Harlan
- Hayes
- Hitchcock
- Kearney
- Lincoln
- Phelps
- Red Willow
- Webster
