Boulder Mail Trail is a 15.7 mile lightly trafficked point-to-point trail located near Escalante, UT that features a river and is rated as difficult. The trail is primarily used for hiking, trail running, and backpacking and is accessible from March until October.
If the "Boulder Mail Trail" seems like an odd title, it's quickly explained. Mules used to carry mail and supplies from Escalante to Boulder (and vice versa) along this route. As such, it's an overland trail as opposed to one that follows a canyon. Boulder Mail Trail does cross three canyons, though, each with its own hiking flavor. Sand Creek, 2.5 miles along the trail (if you start from Boulder Airport), is wet and alive. You'll find water here even in the middle of the summer. Hike two miles farther on and you'll be at Death Hollow. Despite its name, it's also wet all seasons of the year, but has a steep narrowness which can make it dangerous in rainy weather. Last of the canyons, a mile and a half from Death Hollow, is Mamie Creek, best known for a natural bridge. The last four miles of the hike run over the Antone Flats, made up of Navajo sandstone and occasionally shaded by clumps of ponderosa. At the end of the four miles, you'll be able to see Escalante. Slide down into Pine Creek, and you'll be at the Escalante Trailhead. You can also hike this trail in the opposite direction - but this route is more pleasantly downhill.