Alp Creek
USFS trail 158
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.
3.3 mi · Typical grade 12 to 20%
About 1,200 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
- 3.3 mi mapped
- Grade
- Typical grade 12 to 20% (USFS trail class TG05)
- Surface
- native material
- USFS-managed hiker season
- year-round
- USFS-managed uses
- Hiking, Horseback (pack and saddle)
- Motorized status
- Non-motorized (USFS designation)
- 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.
This record is a snapshot of U.S. Forest Service data retrieved on 2026-07-09. It does not reflect current closures, conditions, or seasonal orders. Check with the local ranger district before you go.
Elevation
About 1,200 ft of climbing one way, measured in the harder direction.
- High point
- About 9,150 ft
- Low point
- About 7,950 ft
Estimates, derived from US government elevation data sampled along the USFS-mapped route, computed 2026-07-11. We have not measured these figures in the field.
Plan a day on this trail
A day here means a typical grade of 12 to 20%. Tell the Trip Builder where you are headed and it assembles a day-specific kit with weather, daylight, and terrain in mind.
Build your kitData: U.S. Forest Service, retrieved 2026-07-09.