Poison Spring Canyon is south of Hanksville and runs 16 miles from Highway 95 down to the Dirty Devil River. There’s actually a gravel road which follows the length of the canyon. Its condition changes drastically based on recent storms. This stretch of canyon is the last leg of Section 4 of the Hayduke Trail. Below the map is my description for those walking UP the canyon east to west.
First one must cross the Dirty Devil to head up Poison Spring Canyon. If one has taken the high-water alternate, you will cross where the road does as seen here from the northern rim (along the Happy Maze Alternate):
Your feet will likely look like this:
Follow the road up the inner canyon looking for a few petroglyph panels along the way. After about 4 miles the road will exit the wash and climb out of the inner canyon and follow the rim of the canyon to up above the Black Jump. This feature is seen here from the other side:
There may be some potholes of water just above the Black Jump. If not, the water should appear and even be flowing just a short distance up canyon. It’s fairly quick walking along the road in this section.
Look for the minor petroglyphs on the boulders along the road when a major canyon opens to the south.
Soon water should be running and you will approach the best spring in the canyon. Leave the road and find the constructed and piped improvement in the brush along the northern wall of the canyon.
The canyon continues to be lush for the next mile or so. There are a few spots that can be rough for vehicles after a recent storm.
Soon you will come to where water dries up. At this location there is a big wall with a bunch of petroglyph on the south-facing wall.
Without the stream the walking becomes even faster as one moves up the canyon. The canyon becomes slightly entrenched as it cuts through the Navajo Sandstone.
As the canyon opens up a bit there are a few spots where it’s possible to exit to the south. If heading for the Low-Elevation Henrys Alternate go this way.
The canyon tightens up again and the road actually leaves the canyon briefly. It’s possible to just stay walking in canyon and re-connect with the road after a few bends.
Very soon after this one will see the large culvert ahead at Hwy 95.
If it’s a hot day, this is a great place to get out of the sun and take a break. You deserve it — you just finished Section 4 of the Hayduke Trail!