Avalanche Falls is a 35-foot horsetail waterfall at the top of Flume Gorge in Grafton County, New Hampshire, on Flume Brook.
The falls
Flume Brook drops in a single horsetail pitch at the head of the gorge, in a channel reshaped by a storm in June 1883. The current listed height is 35 feet, up from an older figure of 25 feet for the same drop. The park's own page for Flume Gorge gives a taller number still, 45 feet.
Getting there
The full Flume Gorge loop that reaches the falls runs about 2 miles and takes about 1.5 hours, over packed gravel and boardwalks with uphill grades and stairs. The 2026 season runs May 8 through October 25; on a September 25, 2026 check, hours were 9 a.m. to 5 p.m. Online admission is $18 for adults and $16 for ages 6 to 12, more at the gate ($21 and $19). Timed-entry reservations are recommended and can sell out. A wheelchair-accessible route to the falls is not documented.
When to go
The gorge is open May 8 through October 25; after that it closes for the season and the boardwalks are removed. Best-flow months and crowd patterns beyond possible reservation sellouts are not documented.
On site
The boardwalk route gives close views of the falls, but the gorge's rocks are slippery and visitors are expected to stay on the trail. Dogs are not allowed at Flume Gorge.
Nearby
Flume, The is about 0.1 mile away. Liberty Gorge Cascades is about 0.4 mile, and Pool, The about 0.5 mile. Basin, The is about 1.7 miles away.
Distances are straight-line.