Lava Canyon Falls drops along the Muddy River in Skamania County, Washington.
Lava Canyon Falls was discovered after the 1980 eruption of Mount St. Helens, from which a lahar and flood scoured out a canyon that had been filled with dirt and mud for 1,800 years. The Muddy River's course was redirected to that canyon as a result of the lahar and the floods, and it drops in . Lava Canyon Falls is the largest, 200-foot sheer drop.
On the southeast side of Mount St. Helens National Volcanic Monument at , at 2,440 feet.