Two national parks, a state park overlook and a slab of BLM slickrock all sit within an hour of Main Street, and the only real planning question is heat: everything worth doing here is better before 10am.
Arches National Park
Just north of Moab off US-191, open 24 hours year-round. Entry is $30 per private vehicle, $25 per motorcycle or $15 per person for seven days, and a $55 local annual pass covers Arches and Canyonlands. Delicate Arch is 3 miles round trip with 480 ft of climbing — rangers say they regularly rescue people who underestimate it.
Canyonlands, Island in the Sky
The nearest of Canyonlands' three districts to Moab and the one built for a half-day visit, with overlooks off a short mesa-top road. The districts have no connecting roads and it is two to six hours' drive between them, so treat Island in the Sky, the Needles and the Maze as separate trips rather than one park.
Dead Horse Point State Park
State park on the way to Island in the Sky, open 6am to 10pm with the visitor centre 9am to 5pm. The point stands about 2,000 ft above a gooseneck of the Colorado River, there is the Intrepid mountain-bike trail system with rentals on site, and it is a designated International Dark Sky Park, which is why the 10pm closing matters.
Sand Flats Recreation Area and the Slickrock Trail
Nine thousand acres of BLM and Grand County land just east of town holding the Slickrock Bike Trail, the Hell's Revenge 4x4 route and roughly 30 miles of jeep trails. A seven-day pass is $10 per private vehicle or $5 by bike or motorcycle, $35 annually, and there are 140 first-come campsites at $20 per vehicle per night.
Drive Utah 128 along the Colorado River
The river road leaves US-191 just north of Moab and follows the Colorado upstream through the canyon toward Castle Valley and Cisco. It is free, it takes an hour or two depending on how often you stop, and it is the best thing to do in Moab in the middle of a hot afternoon when the trails are unpleasant.