USFS National Forest System Trails · Custer Gallatin National Forest · Montana · Updated June 2026
Purdy Creek (USFS trail 643) is a 2.5 mi trail in Custer Gallatin National Forest, Montana. Mountain bikes are designated as allowed year-round, with Class 1 e-bikes also designated.
Can I bike Purdy Creek?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | Allowed | year-round |
| Class 1 e-bike (pedal-assist, 20 mph) | Allowed | Jun–Dec |
| Class 2 e-bike (throttle, 20 mph) | Allowed | Jun–Dec |
| Class 3 e-bike (pedal-assist, 28 mph) | Allowed | Jun–Dec |
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
Purdy Creek (USFS trail 643) is a 2.5 mi trail in Custer Gallatin National Forest, 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. USFS records list its surface as native material. No grade band is recorded, so a steepness-based difficulty isn't available for this trail. Mountain bikes are allowed, open year-round in the data. On the electric side, Class 1, Class 2, Class 3 e-bikes are also designated (Jun–Dec) — Class 1 being pedal-assist only, Classes 2 and 3 adding a throttle and higher assisted speed. The route is mapped as USFS Trail Class 4 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 Purdy Creek?
- Yes. Mountain bikes are designated as allowed on Purdy Creek in Custer Gallatin National Forest, year-round, per USFS data.
- Are e-bikes allowed on Purdy Creek?
- Class 1, Class 2, Class 3 e-bikes are designated on Purdy Creek in the USFS data.
- How long is Purdy Creek?
- Purdy Creek measures about 2.5 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Purdy Creek?
- USFS data records the tread surface of Purdy Creek as native material.
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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