Tierdrop is a short, three to four hour technical canyoneering trip inside Arches National Park that involves a short third-class scramble (maybe a couple 4th class moves at the top) followed by three double-rope rappels.
The excursion begins at the Park Avenue Trailhead, roughly two miles inside the park from the main entrance. From the trail head, hike west, back towards the park entrance, less than a couple hundred feet. There will be a large ampitheater of sorts on your right. There is an obvious gully on the left side of this ampitheater. Find a trail that takes you diagonally across the ampitheater and make the short, 3rd class climb up this gully to the top.
At the top of this gully, you will find yourself on the top of the large rock formation. Tierdrop is visible across this formation to your left. There is a tree at the top of Tierdrop and obvious rope burns leading away from the tree down the canyon, which starts off at a very low angle and then steepens towards the bottom. This tree is the anchor for the first double rope length rappel (There was also a boulder slung with webbing a short distance to the right of this tree which could be used as an anchor. "Not Tierdrop" is another canyon slightly to the right of Tierdrop. There was a second boulder slung at the top of this canyon). Make this first rappel off the tree and then hike a short distance down the canyon to a boulder at the edge of a second drop off for the second double rope length rappel. Hike a short distance to your third and final rappel, again a double rope rappel which is approximately 100 feet long, mostly free hanging. From the bottom of this rappel follow the ledge to your right and down climb or complete a fourth, very short rappel. Once down, enjoy the beautiful scenery and hike out the wash until it intersects the Park Ave Trail which leads back to the trail head.
There is a fee to enter Arches National Park, but a permit is not otherwise required.
Two 50 meter ropes or equivalent, Helmet, harness, rappel device, extra beeners, rap rings and webbing.
Another route description can be found here on the ACA's website: