This is a short but super steep and fun side trip from Box Car Loop. The middle portion of the route takes you along a shelf road, and finishes in a straight, flat section. It's a great ATV and UTV route, and the trailhead is located at the exit of Box Car Loop, so it's easy to do both of these trails in the same day.
Drive south from Moab on Highway 191 about 32 miles. Turn right on paved Needles Overlook Road at sign for Canyon Rims Recreation Area soon after mile marker 93. Follow paved road northwest 15 miles and bear right toward Anticline Overlook. Road immediately changes to gravel. Continue another 7.1 miles and watch for small road on left marked 37D.