USFS National Forest System Trails · Helena-Lewis and Clark National Forest · Montana · Updated June 2026
Low Flow (USFS trail 819) is a 4.6 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 Low Flow?
| 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
In Helena-Lewis and Clark National Forest, Montana, Low Flow (USFS trail 819) covers 4.6 mi of National Forest System trail. 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. Underfoot, the trail is recorded 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. 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 Low Flow?
- Yes. Mountain bikes are designated as allowed on Low Flow in Helena-Lewis and Clark National Forest, year-round, per USFS data.
- Are e-bikes allowed on Low Flow?
- No e-bike class (1, 2 or 3) is designated on Low Flow in the USFS data.
- How long is Low Flow?
- Low Flow measures about 4.6 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Low Flow?
- USFS data records the tread surface of Low Flow 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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