Mt Flume is the southernmost peak on Franconia Ridge and the first mountain the Pemigewasset Loopers encounter after leaving the Lincoln Woods Trailhead. I climbed in via the Osseo Trail which provides a relatively gradual ascent, climbing 3150′ feet in 5.6 miles, except for a series of wooden ladders as you near treeline. While I have hiked the Osseo twice previously, in winter and once in the dark after a counterclockwise Pemi Loop, I’d never seen it with its “leaves on” and kicked myself for not going up Flume this way more often. It really is a lovely trail and much easier to climb than the other routes up the peak.
I left the Lincoln Woods Trailhead, which was surprisingly crowded for an early Friday morning, and headed out the dreaded Lincoln Woods Trail. It’s not a bad trail, but it’s the main gateway to the Pemigewasset Wilderness, which means I’ve hiked it hundreds of times, which gets a little monotonous. It is a very fast trail to hike and I can usually get up to 3 mph on it because it’s so flat and wide, so the hike out to the Osseo Trailhead went by quickly.
The Osseo Trail runs through a pretty wooded area before it starts a gradual climb up an eastern ridge to the main Franconia ridgeline. While the trail runs alongside an unnamed stream, it does so some 100 feet up a steep slope so the stream is practically inaccessible without a herculean effort. I’d packed extra water since we’re in the midst of a bad drought, but I made a mental note for future forrays, not to count on this stream for water in the future.
The trail surface is mainly dirt until 2.1 miles up when the trail begins to switch back and forth to gain elevation and tree roots and rocks make their appearance. The trail soon enters a very steep section, punctuated by wooden and rock stairs, before passing a viewpoint on the right which overlooks the south side of Owlshead Mountain and the Bonds, including a great view Bondcliff. I stopped for a snack and studied the terrain just north, examining a ridge from Mt Flume down to Lincoln Brook, to see if it could be used as a shortcut. I saw a reference to a Dirrettissima Route that used something in the vicinity and wondered if and how that hiker had been able to hike down this ridge: it looked impossibly steep to me.
More rock steps and ladders begin above the viewpoint before the trail flattens out when it comes to Franconia Ridge beofre climbing briefly to the Flume Slide junction and a short exposed scramble to the top of Mt Flume. I had a vague recollection of this section from my Pemi loop of a few years ago, but I wouldn’t know it from Adam if I hadn’t known where I was on a map.
I passed the Flume Slide junction and continued to the summit, which was fairly crowded for a Friday afternoon, in summer. I took in the view of nearby Mt Lincoln and then turned to hike back down the way I’d come, chatting with a few hikers I’d passed earlier. In the span of 2 minutes, three people asked whether they should climb down the Flume Slides Trail.
My response: that’d be a great way to get a ride in a National Guard Helicopter! So no. It’s wet and climbing down the slippery ledges is ill-advised. All that detail is in the White Mountain Guide, if only people who buy it and read it instead of relying on AllFails or Facebook for their trail beta (said the curmudgeon).
Alternative Routes: There are two other ways to climb Mt Flume. The first is via the Flume Slide Trail and the second is to follow the Franconia Ridge Trail south from Mt Liberty. The latter is so frequently hiked that it’s often referred to as “Fliberty” by the locals.
History: The Osseo Trail used to run up the west side of Whaleback Mountain before climbing to Franconia Ridge. It was re-routed in the 1980s following the construction of the Clearbrook condos at the previous trailhead. That old trail is still unofficially maintained and is used by bushwhackers to climb South Whaleback.