Lava Falls Trail is a 2.8 mile lightly trafficked out and back trail located near Colorado City, Arizona that features a river and is rated as difficult. The trail is primarily used for hiking and trail running and is accessible from September until May.
The description of this trail is misleading. There are large rapids at the bottom but I wouldn't call it a waterfall.
The trail is grueling and hard to find at times, but it was fun to go to the bottom of the Grand Canyon and back in less than a day.