The Flume Gorge, 852 Daniel Webster Hwy. (SR 3), at the s. end of Franconia Notch State Park, is a chasm extending nearly 800 feet along the flank of Mount Liberty. A mountain stream tumbles in a series of waterfalls and pools between its 60- to 90-foot-high granite walls. An optional shuttle bus takes visitors the first half-mile; it is then a 1.5-mile walk through the flume back to the visitor center. A well-constructed boardwalk leads through the gorge; there are, however, some steep grades. Within the flume are two covered bridges, waterfalls and cascades.