Madison Arm Loop (snowmo)
USFS trail 919
The route in 3D
Fly this trail over real terrain
USGS and partner elevation data build the terrain, and the US Forest Service centerline draws the route.
18.5 mi · Typical grade 0 to 5%
About 100 ft between the route's high and low points. An estimate from US government elevation data, computed 2026-07-11; not measured in the field.
Trail facts
- Length
- 18.5 mi mapped
- Grade
- Typical grade 0 to 5% (USFS trail class TG01)
- Surface
- native material
- Designation
- National trail designation
- National forest
- Custer Gallatin National Forest
Length is the trail as the Forest Service maps it, not a trip distance. Hike out and back and you will cover it twice; check the shape of the route before you count on the figure.