Moshannon State Forest Quehanna Highway Backcountry Loop
Cold War ruins in Pennsylvania's nuclear wilderness
The Quehanna Highway backcountry loop threads through what used to be a classified nuclear research facility, where Curtiss-Wright tested experimental reactors in the 1950s. The main route follows old security roads past abandoned bunkers and concrete foundations, with a technical climb over Medix Grade that’ll test your low-range skills. The highlight is the reactor site clearing, where massive concrete pads and rusted infrastructure tell the story of Pennsylvania’s atomic age.
This is difficult terrain with steep, rocky climbs and loose shale descents that demand good tires and experience. High clearance essential, locking differentials recommended for the worst sections. Spring through fall offers the best conditions, though fall colors make the remoteness worth the extra effort. No permits but respect the historical sites. Bring full camping kit and extra fuel – you’re hours from civilization in some of the most isolated forest in Pennsylvania.
Trail Specs
| Difficulty | Difficult |
|---|---|
| Trail Type | Backcountry |
| Surface | Mixed |
| Features | Camping, Historic, Remote, Scenic |
| Length (miles) | 28 mi / 45.1 km |
| Duration | Full day |
| Max elevation (ft) | 2180 ft |
| Best season | May-October |
| Minimum vehicle | High-clearance 4WD with low range |
| Nearest town | Karthaus, PA |
| Land manager | Pennsylvania DCNR Bureau of Forestry |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Start coordinates | |
| End coordinates | |
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Location
Trail Conditions
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Frequently asked questions
Can a lifted Jeep Wrangler or 4Runner handle this trail, or does it need serious modifications?
A stock high-clearance 4WD with low range will get through, but the technical climbs and mixed surfaces reward a skid plate setup and all-terrain tires. Lifted rigs with lockers will have a much easier time on the loose, rutted sections. Unibody crossovers and 2WD trucks have no business here.
When does this trail become impassable, and can you run it in early spring?
Best window is May through October — spring snowmelt and late-season rains turn the forest floors into axle-deep mud that can swallow a rig fast. Early spring access is a gamble; Pennsylvania's freeze-thaw cycles wreck these roads through April. Stick to summer and early fall for the most predictable conditions.
Do you need a permit to run this loop or camp overnight in Moshannon State Forest?
No permit is required for day use or dispersed camping in Moshannon State Forest. Pennsylvania DCNR allows dispersed camping on state forest land without a fee, but you're limited to 30 consecutive days at any one site and must follow Leave No Trace rules. No registration needed — just show up clean and leave it cleaner.
What's the hardest section of the loop and what makes it technically demanding?
The technical climbs scattered through the interior of the loop are where rigs get sorted out — steep grades on loose shale and dirt that get seriously slick when wet, with off-camber exposure and tight tree lines leaving little room for line correction. The elevation gain is gradual overall, but the punch sections hit fast and punish drivers who aren't already in low range. Momentum management matters here.
Are the water crossings on this trail actual wheel-submerging fords, and how do they change after rain?
Yes — there are genuine water crossings, not just wet pavement, and after heavy rain they can rise quickly and obscure the bottom. Always walk a crossing before you commit; what looks like 12 inches can hide rocks and soft bottom that drop your axle another foot. Build extra time into your plan after any rain in the 48 hours before your run.
Trail track
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