Pothole arches are formed when rainwater eventually erodes the bonds between sand grains and deepens a sandstone surface depression puddle into a hole big enough to punch through an adjacent cliff wall.
There are lots of pothole arches in Canyonlands, including one on the edge of adjacent Poison Spider mesa. The trail out to this particular "Pothole Arch" is a fun singletrack that branches right off the Amasa Back / Cliffhanger
Trail less than a mile after you cross the water pipe.
Follow the singletrack as it parallels the low bluff on your right called, "The Billboard". The trail is really engaging, and a bit tricky to follow in places. Watch for white paint dashes.
There are lots of short, technical ups and downs to hold your attention, and plenty of freeform slickrock riding if that interests you. Have fun on the rocky areas, but if you are leaving tracks in dirt, you are seriously screwing up. Please don't be a pathetic punter - crappy form has closed more than one ride.
When the Billboard comes to an end, attentive riders will note a singletrack trail branching off to the right. This is Rockstacker
, a super-fun, super-technical laugh-riot that is an order of magnitude harder than what you've been riding.
Skip this right turn for now and continue out the original singletrack until it fades into golden slickrock riding. There is a faint, rust-colored paint stripe to guide you from here. Stay on this paint strip until you reach the arch, which is really cool, but really not as impressive as you were expecting. Visit Bullethole Arch south of Moab for some perspective.
Enjoy the amazing views in the area, continue out the 'Back to ride some slickrock, then retrace your steps and exit via Rockstacker
, or Amasa Back / Cliffhanger