Mount Flume, located just east of I-93 & US-3 (aka Franconia Notch Parkway) in Franconia Notch, is the southernmost and shortest of the five peaks on the very popular Franconia Ridge. Like Mount Lafayette, the northernmost peak of the Franconia Ridge, Mount Flume can be hiked via a short loop hike that is close to the road. Reasons to hike this peak include: (1) the 9.9 mile loop hike with a Mount Liberty summit, (2) the class 3 Flume Slide that is nearly always wet due to many spring seeps, (3) easy access from I-93 and US-3 (still separate at this point and about 2 hours from Boston), and (4) fewer people than the Mount Lafayette loop. Mount Flume ranks 25th on the list of 48 NH 4000' peaks.
Flume Slide Route: The shortest way to reach the summit is a 4.8 mile route that includes the class 3 Flume Slide. Start at the hikers' parking lot (1400') off of US-3 just north of the Flume Visitor Center. Head north on the Whitehouse Trail for 0.8 miles before turning east on to the Liberty Springs Trail (most direct route to Mount Liberty). In 0.6 miles turn right (southeast) on to the Flume Slide Trail. In 2.6 miles you will reach the foot of the Flume Slide - a rockslide through the trees which you will need to climb up. The rock here is very solid and angular with good holds even in the rain. The slide lasts for 0.7 miles after which you will reach the Franconia Ridge Trail junction just 0.1 miles south of the Mount Flume summit.
Liberty Springs Route: An alternate 5.1 mile class 1 route to reach Mount Flume is via Mount Liberty (4459'). Follow the directions above, however, this time do not take the Flume Slide Trail. From the Liberty Springs - Flume Slide Trails junction continue east on the Liberty Springs Trail 2.3 miles to Franconia Ridge before heading 0.3 miles south to Mount Liberty. From the Mount Liberty summit go southeast along the Franconia Ridge Trail 1.1 miles to the Mount Flume summit. Note: the Liberty Springs Trail is part of the Appalachian Trail.
Combine the two hikes above to do a popular 9.9 mile loop hike (technically a lollipop with 1.4 mile overlap).
Osseo Route: A 5.6 mile hike using the Osseo Trail is the other popular way to reach Mount Flume, starting from the southeast at the Lincoln Woods Visitor Center on the Kancamangus Highway (NH SR-112). From the visitor center take the Lincoln Woods Trail 1.4 miles north before turning west on to the Osseo Trail heading northwest. In 4.1 miles you will reach the junction with the Flume Slide Trail and the Franconia Ridge Trail. Continue north 0.1 miles on the Franconia Ridge Trail to the summit.
Note from John: I've described Mount Flume rather than Mount Liberty (131' taller) because I think Mount Flume is a much more interesting peak given the Flume Slide. A consequence, however, is that all the hiking approaches for Mount Liberty are described above - I don't know of any bushwacking routes ;-) Mount Liberty ranks 18th in height in NH's White Mountains.
FRANCONIA NOTCH / US-3 TRAILHEAD: Take I-93 into Franconia State State Park and turn off on to US-3 when you see signs for The Flume where there is a large seasonal visitor center. The Flume is the bottom part of the Flume Brook which an entrance fee is charged to see the rock gorge (though I've heard you can get in w/o a fee during the winter). Continue north on US-3 to the hikers' parking lot where you can reach the Flume Slide and Liberty Springs Trails.
LINCOLN WOODS TRAILHEAD: The Lincoln Woods Visitor Center is the main entrance into the Pemigewasset Wilderness and also provides access to the Osseo trail. The parking lot is located on NH SR-112, aka the Kancamaugus Highway, about 4 miles east of I-93, just across the Pemigewasset River. The parking lot has restrooms, a payphone, and a ranger station. A WMNF Parking pass is required to park here.
None if parking at the US-3 traihead in Franconia Notch State Park. If you are parking in the White Mountain National Forest (WMNF), e.g. climbing the Osseo Trail, then you will need a WMNF Parking Pass. See the Mount Washington Page Red Tape Section for the Parking Pass requirements and fees.
You can climb this peak year round. Be prepared for snow during the winter. The Flume Slide may be tricky if it ices up.
There is a tent platform at the Liberty Springs Tentsite (3800') 0.3 miles below Franconia Ridge on the Liberty Springs Trail. There is not much space here and on occasion you may run into people who stay here for up to a week (Ref: John). A better option is to do some backcountry camping on the wooded ridge between Mount Liberty and Mount Flume (don't worry about your view - both summits are exposed). If you do this make sure you check the USFS White Mountain Backcountry Camping Rules.
See the Mount Lafayette Page for conditions information. Mount Lafayette is just 4.9 miles north of Mount Flume via the Franconia Ridge Trail.