USFS National Forest System Trails · Custer Gallatin National Forest · Montana · Updated June 2026
40012 (USFS trail 40012) is a 1.8 mi trail in Custer Gallatin National Forest, Montana. Mountain bikes are designated as allowed, Jan–Aug, December, with Class 1 e-bikes also designated.
Can I bike 40012?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | Allowed | Jan–Aug, December |
| Class 1 e-bike (pedal-assist, 20 mph) | Allowed | Jan–Aug, December |
| Class 2 e-bike (throttle, 20 mph) | Allowed | Jan–Aug, December |
| Class 3 e-bike (pedal-assist, 28 mph) | Allowed | Jan–Aug, December |
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
40012 (USFS trail 40012) is a 1.8 mi trail in Custer Gallatin National Forest, Montana. This profile summarizes what the official US Forest Service trail record says about riding it: how long the trail is, what it's built on, how steep the route grades out, and which forms of bike use the agency has designated. The tread is mapped as native material. Its grade-based difficulty is Intermediate (grade band +8-10%) — a moderate steepness profile derived from USFS slope data, not a technical mountain-bike rating. Mountain bikes are allowed, with a Jan–Aug, December season in the data. The record additionally permits Class 1, Class 2, Class 3 e-bike use, Jan–Aug, December; recall that Class 1 is pedal-assist, while Class 2 adds a throttle and Class 3 a higher cutoff speed. 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. Treat this as a planning reference rather than a live conditions report, and verify any time-sensitive closure or order with the ranger district that manages Custer Gallatin National Forest.
Frequently asked questions
- Can you mountain bike on 40012?
- Yes. Mountain bikes are designated as allowed on 40012 in Custer Gallatin National Forest, typically Jan–Aug, December, per USFS data.
- Are e-bikes allowed on 40012?
- Class 1, Class 2, Class 3 e-bikes are designated on 40012 in the USFS data.
- How long is 40012?
- 40012 measures about 1.8 mi in total, summed across its mapped National Forest System segments.
- What is the surface of 40012?
- USFS data records the tread surface of 40012 as native material.
- How difficult is 40012?
- Its grade-based difficulty is Intermediate (grade band +8-10%), 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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