USFS National Forest System Trails · Custer Gallatin National Forest · Montana · Updated June 2026
West Pine (USFS trail 139) is a 5.3 mi trail in Custer Gallatin National Forest, Montana. Mountain bikes are designated as allowed year-round, with no Class 1 e-bike designation on record.
Can I bike West Pine?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | Allowed | year-round |
| Class 1 e-bike (pedal-assist, 20 mph) | Restricted | — |
| Class 2 e-bike (throttle, 20 mph) | Restricted | — |
| Class 3 e-bike (pedal-assist, 28 mph) | Restricted | — |
Zooming out: across Custer Gallatin National Forest, 98% of rideable trail miles are open to mountain bikes — a Bike Access Grade of A.
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About this trail
West Pine (USFS trail 139) runs 5.3 mi through Custer Gallatin National Forest in Montana. Everything below comes straight from the US Forest Service National Forest System Trails dataset — length, surface, slope-derived difficulty, and the specific bike and e-bike designations on record — so you can check legality before you load up. Underfoot, the trail is recorded as native material. Its grade-based difficulty is Advanced (grade band +12-20%) — a steep steepness profile derived from USFS slope data, not a technical mountain-bike rating. Mountain bikes are allowed, open year-round in the data. No e-bike class (1, 2 or 3) is designated on this trail in the USFS data, so treat it as a non-motorized route unless a posted order says otherwise. The route is mapped as USFS Trail Class 3 on the agency's 1-to-5 development scale, where 1 is the most primitive, minimally maintained tread and 5 is the most developed. For day-of certainty on closures or seasonal orders, check directly with the ranger district, since this reflects the USFS data as of the latest refresh.
Frequently asked questions
- Can you mountain bike on West Pine?
- Yes. Mountain bikes are designated as allowed on West Pine in Custer Gallatin National Forest, year-round, per USFS data.
- Are e-bikes allowed on West Pine?
- No e-bike class (1, 2 or 3) is designated on West Pine in the USFS data.
- How long is West Pine?
- West Pine measures about 5.3 mi in total, summed across its mapped National Forest System segments.
- What is the surface of West Pine?
- USFS data records the tread surface of West Pine as native material.
- How difficult is West Pine?
- Its grade-based difficulty is Advanced (grade band +12-20%), derived from USFS slope data. This reflects steepness, not technical mountain-bike difficulty.
How we read this data
Grade-based difficulty above is the USFS grade (route steepness), not a technical mountain-bike rating — a gentle-grade trail can still be rocky or technical, and vice versa. Bike and e-bike status come verbatim from the USFS managed-use fields for this trail; we never infer access we can't cite. See our methodology for how the dataset is built and what each field means.
Where it is
Approximate location of Custer Gallatin National Forest (USFS trail geometry isn't mapped).
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