These connecting trails follow the bed of the old Beebe River Railroad up to Flat Mountain Pond, a large, remote pool high in the Sandwich Range Wilderness. This is a great trip for advanced mountain bikers; novice/intermediate bikers should expect a challenge. Hikers enjoy a relatively easy trek because there's little gain in elevation.
Guinea Pond Trail begins at a Forest Service gate and climbs a dirt road 0.2 mile to the railroad bed. While the trail keeps to the rail bed as best it can, at times the trail must detour around sections reclaimed by beaver ponds. Just over 1 mile in, there are a couple of Y junctions; take the second one and bear left to continue on the main, unmarked trail and begin an ascent.
After crossing three wooden bridges, the trail bends right to rejoin the railroad bed. The trail then reaches the junction of the Mead and Black Mountain Pond trails. Continue straight on the Guinea Pond Trail.
After several wide stream crossings, the trail reaches the marked 0.2-mile spur on the left to the pond itself. The onward trail continues along the rail bed to the 2.5-mile mark, where it detours again to avoid water (follow the yellow arrow to the left). This section is winding and rough, traversing large rocks and gnarly roots. The route finally rejoins the corridor after 0.2 mile and offers mostly smooth going to the Flat Mountain Pond Trail junction.
The Flat Mountain Pond Trail quickly gains elevation, soon passing the Gleason Trail junction. Watch for a sign on the left that marks the boundary of the Sandwich Range Wilderness; from here up to Flat Mountain Pond, the rail bed doubles as that boundary. Note: Bike riding is not permitted in the wilderness, so be sure to stay on the trail.
Eventually, the trail turns along the Great Horseshoe, the sharpest turn on any of New Hampshire's old logging railroads. After navigating boulders, tricky streams and other obstacles for about 2 miles, turn right at the trail junction and head toward the pond for beautiful views of Flat Mountain and Whiteface Intervale. A shelter is available for overnight camping. Trail users can either retrace their steps back along the Guinea Pond Trail or keep heading along the Flat Mountain Pond Trail toward Whiteface Intervale Road.
The Guinea and Flat Mountain Pond Trails run between
I did this trail with my girlfriend and dog (adventure pug) a couple weekends ago.
The guinea pond trail has quite a bit of flooding and requires some bushwhacking, but it's doable.
The trail itself from the start of guinea pond to flat mountain pond is about 9.5 miles, but it's relatively flat. It took us about 4.5 hours on the way though (with 45 mins for breaks) and 3.5 hours on the way back.
Next time we'll be starting at a different trail head to avoid the guinea pond flooding.
Directions tell you to take Right at Y. This "Y" is almost non-existent at this point, the left fork now leading into the beaver pond. There is another Y only 10 yds past. Left fork leads to trail, right fork to power lines.
Very cool trail with many options for varying activity levels. Can "out-and-back" to any number of points for an easy beautiful walk or extend to a number of peaks including Mt Israel. Lots of wildflowers in the spring but also many ticks.

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