USFS National Forest System Trails · Superior National Forest · Minnesota · Updated June 2026
Mud Lake Spur D (USFS trail T6-604D) is a 0.9 mi trail in Superior National Forest, Minnesota. Mountain-bike use here is accepted but discouraged in USFS data, with Class 1 e-bikes also designated.
Can I bike Mud Lake Spur D?
| Use | Status | Season on record |
|---|---|---|
| Mountain bike | Accepted but discouraged | — |
| Class 1 e-bike (pedal-assist, 20 mph) | Allowed | May–Nov |
| Class 2 e-bike (throttle, 20 mph) | Allowed | May–Nov |
| Class 3 e-bike (pedal-assist, 28 mph) | Allowed | May–Nov |
Zooming out: across Superior National Forest, 22% of rideable trail miles are open to mountain bikes — a Bike Access Grade of D.
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About this trail
Mud Lake Spur D (USFS trail T6-604D) is a 0.9 mi trail in Superior National Forest, Minnesota. 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. Underfoot, the trail is recorded as native material. Based on slope, this is a Easy trail (grade band +0-5%); that reflects gentle gradient and is not the same as a technical MTB difficulty rating. For traditional mountain bikes, use is discouraged according to USFS data. On the electric side, Class 1, Class 2, Class 3 e-bikes are also designated (May–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 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. 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 Superior National Forest.
Frequently asked questions
- Can you mountain bike on Mud Lake Spur D?
- Mountain-bike use on Mud Lake Spur D is discouraged in USFS records, though Class 1 e-bike use is designated. Confirm current rules with the managing ranger district.
- Are e-bikes allowed on Mud Lake Spur D?
- Class 1, Class 2, Class 3 e-bikes are designated on Mud Lake Spur D in the USFS data.
- How long is Mud Lake Spur D?
- Mud Lake Spur D measures about 0.9 mi in total, summed across its mapped National Forest System segments.
- What is the surface of Mud Lake Spur D?
- USFS data records the tread surface of Mud Lake Spur D as native material.
- How difficult is Mud Lake Spur D?
- Its grade-based difficulty is Easy (grade band +0-5%), 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 Superior National Forest (USFS trail geometry isn't mapped).
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