nonprofit

Yellowstone River Parks Association

Billings land-and-trails nonprofit (est. 1991) stewarding 2,000+ acres along the Yellowstone River Greenway, with volunteer trail-build days.

Hiking⚠ Needs verification

Seasonal trail-build volunteer days — see site

Beginner-friendlyDog-friendlyFreeSummer

Build and maintain trails across 2,000+ acres of riverfront park land.