Main South Fork Trail
1 days · 39.7 mi · hard · Point-to-point
Quick facts
What the Main South Fork Trail is known for
This 39.7-mile route travels through the Bob Marshall Wilderness near the South Fork Flathead River. With 4,636 feet of gain and substantial mileage, it is a hard backpacking trip.
Elevation profile
Elevation ranges from 12,388 ft to 16,093 ft over 39.7 mi. Measured from OSM geometry (approximate).
- Uphill 21.4 mi · 54%
- Downhill 9.8 mi · 25%
- Flat 8.4 mi · 21%
Ridgefold breaks every route into uphill, downhill, and flat — see the full per-day breakdown in the app.
How hard is the Main South Fork Trail?
On the Ridgefold Difficulty Index, the Main South Fork Trail scores 17/100, a relative rating across the 1,243 trails we've mapped, blending distance, elevation gain, and steepness. It is a comparison within our set, not an official rating.
Frequently asked questions
How much elevation gain is on the Main South Fork Trail?
The Main South Fork Trail climbs roughly 4,636 ft total — about 117 ft per mile, topping out near 5,066 ft.
Related trails
Sources & attribution
Route geometry from the USDA Forest Service National Forest System Trails dataset (EDW), a work of the US federal government in the public domain. Stats are approximate and may differ from official surveys; permit rules and conditions change — verify with the managing authority before your trip. Last reviewed July 2026.