USFS National Forest System Trails · Custer Gallatin National Forest · Montana · Updated June 2026
Marble Mountain (USFS trail 168) is a 5.8 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 Marble Mountain?
| 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.
Watch Custer Gallatin National Forest for access changes
Email me when USFS mountain-bike or e-bike designations change for trails in Custer Gallatin National Forest. Free, unsubscribe anytime.
About this trail
Marble Mountain (USFS trail 168) is a 5.8 mi trail in Custer Gallatin National Forest, Montana. The figures here are pulled from the official US Forest Service trail data for Custer Gallatin National Forest, covering the trail's mileage, tread, grade band, and the bike and e-bike uses the agency lists as designated. The tread is mapped as native material. USFS slope data puts it in the Advanced band (grade band +12-20%), meaning a steep climb — keep in mind this measures steepness, not trail technicality. Bike use is designated as allowed year-round. 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 2 on the agency's 1-to-5 development scale, where 1 is the most primitive, minimally maintained tread and 5 is the most developed. Because conditions, closures, and local orders change between data refreshes, confirm the current status with the managing ranger district before you ride.
Frequently asked questions
- Can you mountain bike on Marble Mountain?
- Yes. Mountain bikes are designated as allowed on Marble Mountain in Custer Gallatin National Forest, year-round, per USFS data.
- Are e-bikes allowed on Marble Mountain?
- No e-bike class (1, 2 or 3) is designated on Marble Mountain in the USFS data.
- How long is Marble Mountain?
- Marble Mountain measures about 5.8 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Marble Mountain?
- USFS data records the tread surface of Marble Mountain as native material.
- How difficult is Marble Mountain?
- 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).
Where to stay near Custer Gallatin National Forest
Find hotels, cabins, and vacation rentals near Custer Gallatin National Forest — plan your ride.
Top-rated places to stay near Custer Gallatin National Forest
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Riding Custer Gallatin National Forest?
Trail-access updates and trip ideas by email.