USFS National Forest System Trails · Arapaho and Roosevelt National Forests · Colorado · Updated June 2026
Bull Mtn Annex (USFS trail 117.1) is a 0.5 mi trail in Arapaho and Roosevelt National Forests, Colorado. Mountain bikes are designated as allowed, Jun–Nov, with Class 1 e-bikes also designated.
Can I bike Bull Mtn Annex?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | Allowed | Jun–Nov |
| Class 1 e-bike (pedal-assist, 20 mph) | Allowed | Jun–Nov |
| Class 2 e-bike (throttle, 20 mph) | Allowed | Jun–Nov |
| Class 3 e-bike (pedal-assist, 28 mph) | Allowed | Jun–Nov |
Zooming out: across Arapaho and Roosevelt National Forests, 99% of rideable trail miles are open to mountain bikes — a Bike Access Grade of A.
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About this trail
In Arapaho and Roosevelt National Forests, Colorado, Bull Mtn Annex (USFS trail 117.1) covers 0.5 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. USFS records list its surface as native material. Its grade-based difficulty is Easy (grade band +5-8%) — a gentle steepness profile derived from USFS slope data, not a technical mountain-bike rating. Mountain bikes are allowed, with a Jun–Nov season in the data. On the electric side, Class 1, Class 2, Class 3 e-bikes are also designated (Jun–Nov) — 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 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 Bull Mtn Annex?
- Yes. Mountain bikes are designated as allowed on Bull Mtn Annex in Arapaho and Roosevelt National Forests, typically Jun–Nov, per USFS data.
- Are e-bikes allowed on Bull Mtn Annex?
- Class 1, Class 2, Class 3 e-bikes are designated on Bull Mtn Annex in the USFS data.
- How long is Bull Mtn Annex?
- Bull Mtn Annex measures about 0.5 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Bull Mtn Annex?
- USFS data records the tread surface of Bull Mtn Annex as native material.
- How difficult is Bull Mtn Annex?
- Its grade-based difficulty is Easy (grade band +5-8%), 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 Arapaho and Roosevelt National Forests (USFS trail geometry isn't mapped).
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