This is a really fun trail that winds all the way down to the Colorado River. Some of the more challenging spots are in Lathrop Canyon as you head down the trail towards the river. There is a cool picnic area that requires a day-use permit at the bottom of this trail, but camping isn't allowed. You'll also need to pay a fee to enter the park.
From downtown Moab, take Highway 191 north about 11 miles and turn left on Highway 313. Follow signs to Canyonlands National Park. Total distance about 32 miles. You can also reach the White Rim by driving Potash Road Trail