The Conway granite of the walls of the flume were formed 200 million years ago in Jurassic times. Basalt dikes, erosion and frost have combined to carve a spectacular 70-90 feet deep, narrow flume. Visitors can walk down to view just the flume and return or complete the loop. Continue on to see a number of natural features on the two-mile loop plus you'll cross the oldest covered bridge in New Hampshire.
If you go:
Open early May though most of October from 8:30 a.m. to 5 or 5:30 p.m. Admission, discounts for children. Discovery Pass, which also includes the Cannon Mountain Aerial Tramway can be purchased. Large parking lot. No pets. Bus available to start the Flume Gorge section but you must still climb a lot of stairs and walk uphill. The visitor center has restrooms, cafeteria, a film about Franconia State Park and a few exhibits.
Links:

852 Daniel Webster Hwy
Lincoln, New Hampshire 03251 USA
nhparks@dred.nh.gov
Mailing address:
NH Department of Natural and Cultural Resources
172 Pembroke Rd
Concord, NH 03301 USA
Phone Numbers:
Flume Gorge
+1 (603) 745-8391
+1 (603) 745-8391