USFS National Forest System Trails · Eldorado National Forest · California · Updated June 2026
Porthole Gap 4wd Trail (USFS trail 17E32) is a 1.4 mi trail in Eldorado National Forest, California. Mountain-bike use here is not designated in USFS data, with Class 1 e-bikes also designated.
Can I bike Porthole Gap 4wd Trail?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | — | |
| Class 1 e-bike (pedal-assist, 20 mph) | Allowed | Apr–Dec |
| Class 2 e-bike (throttle, 20 mph) | Allowed | Apr–Dec |
| Class 3 e-bike (pedal-assist, 28 mph) | Allowed | Apr–Dec |
Zooming out: across Eldorado National Forest, 94% of rideable trail miles are open to mountain bikes — a Bike Access Grade of A.
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About this trail
In Eldorado National Forest, California, Porthole Gap 4wd Trail (USFS trail 17E32) covers 1.4 mi of National Forest System trail. 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. The tread is mapped as native material. Its grade-based difficulty is Advanced (grade band 12-20%) — a steep steepness profile derived from USFS slope data, not a technical mountain-bike rating. Note that mountain-bike use here is not designated in USFS records — confirm with the ranger district before riding. The record additionally permits Class 1, Class 2, Class 3 e-bike use, Apr–Dec; 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. 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 Porthole Gap 4wd Trail?
- Mountain-bike use on Porthole Gap 4wd Trail is not designated in USFS records, though Class 1 e-bike use is designated. Confirm current rules with the managing ranger district.
- Are e-bikes allowed on Porthole Gap 4wd Trail?
- Class 1, Class 2, Class 3 e-bikes are designated on Porthole Gap 4wd Trail in the USFS data.
- How long is Porthole Gap 4wd Trail?
- Porthole Gap 4wd Trail measures about 1.4 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Porthole Gap 4wd Trail?
- USFS data records the tread surface of Porthole Gap 4wd Trail as native material.
- How difficult is Porthole Gap 4wd Trail?
- Its grade-based difficulty is Advanced (grade band 12-20%), 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 Eldorado National Forest (USFS trail geometry isn't mapped).
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