Grandstaff Canyon is one of several hikes close to Moab that are recommended by multiple…read moreguidebooks, so be prepared to share the trail with others. Regardless, it is good for a half-day adventure, especially in warmer months. Being on BLM land, there's no entrance fee. It's also dog-friendly, so you'll see plenty of pups on the hike, usually sopping wet and happy. (But maybe don't go out of your way to pet them in late spring, when there's also plenty of poison ivy along the trail). The hike is about 5 miles total (round trip) that ends in Morning Glory natural bridge, which turns out NOT to be an arch. (Natural bridges form primarily from the flow of a stream, whereas natural arches are typically a combo of wind and water).
Over half of the hike is fairly flat, along a beautiful, bucolic, wooded valley surrounded by high sandstone cliffs. The trail crosses and re-crosses a clear, burbling stream punctuated by quiet pools and mini falls. We found plenty of spots to pull off the trail and enjoy the beauty, and I stopped to dip my toes in at one point. If you continue on beyond this flatter section, there's a gentle uphill grade, some on open sandstone, to get to the rear of the canyon. The reward for this extra effort is the stunning natural bridge, which in hot weather can provide a cool, shady respite before retracing your steps back to the trailhead.
Due to extreme popularity, and the small lot, parking can be a pain here. Coming from Moab, we just continued past the lot for a hundred yards or so, turned left, and parked in the large, raised dirt area on the Colorado River side of the road. There were plenty of spots, and it was a short walk back to the trailhead.