USFS National Forest System Trails · Helena-Lewis and Clark National Forest · Montana · Updated June 2026
Sixteen Mile (USFS trail 644) is a 2.7 mi trail in Helena-Lewis and Clark National Forest, Montana. Mountain bikes are designated as allowed year-round, with no Class 1 e-bike designation on record.
Can I bike Sixteen Mile?
| 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 Helena-Lewis and Clark National Forest, 91% of rideable trail miles are open to mountain bikes — a Bike Access Grade of A.
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About this trail
Sixteen Mile (USFS trail 644) runs 2.7 mi through Helena-Lewis and Clark National Forest in Montana. The figures here are pulled from the official US Forest Service trail data for Helena-Lewis and Clark 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. No grade band is recorded, so a steepness-based difficulty isn't available for this trail. Bike use is designated as allowed year-round. The agency lists no Class 1, 2 or 3 e-bike designation here; absent a local order to the contrary, that means e-bikes are not an allowed use on this trail. 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. 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 Sixteen Mile?
- Yes. Mountain bikes are designated as allowed on Sixteen Mile in Helena-Lewis and Clark National Forest, year-round, per USFS data.
- Are e-bikes allowed on Sixteen Mile?
- No e-bike class (1, 2 or 3) is designated on Sixteen Mile in the USFS data.
- How long is Sixteen Mile?
- Sixteen Mile measures about 2.7 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Sixteen Mile?
- USFS data records the tread surface of Sixteen Mile 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 Helena-Lewis and Clark National Forest (USFS trail geometry isn't mapped).
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