One of the fringe benefits of the Zion Canyon shuttle bus  is the great bicycling that's resulted from the lack of automobile traffic. It used to be way too scary to bike along the narrow, traffic-choked Zion Canyon Scenic Drive, but now it's a joy.
On the stretch of road where cars are permitted—between the visitor center  and Canyon Junction (where the Zion-Mount Carmel Highway meets Zion Canyon Scenic Drive)—the two-mile, paved Pa'rus Trail  is open to bikers as well as pedestrians and makes for easy, stress-free pedaling.
If you decide you've had enough cycling, every shuttle bus has a rack that can hold two bicycles. Bike parking is plentiful at the visitor center, Zion Lodge, and most trailheads.
Outside the Zion Canyon area, Kolob Terrace Road is a good place to stretch your legs; it's 22 miles to Kolob Reservoir .
There's really no place to mountain bike within the park, but there are good mountain biking spots, including places to practice slickrock riding, just outside the park boundaries. It's best to stop by one of the local bike shops for advice and a map of your chosen destination.
Rock-climbers come to scale the high Navajo sandstone cliffs; after Yosemite , Zion National Park  is the nation's most popular big-wall climbing area. However, Zion's sandstone is far more fragile than Yosemite's granite, and it has a tendency to crumble and flake, especially when wet. Beginners should avoid these walls—experience with crack climbing is a must.
For route descriptions, pick up a copy of Desert Rock, by Eric Bjørnstad, or Rock Climbing Utah, by Stewart M. Green. Both books are sold at the visitor center bookstore. The backcountry desk in the visitor center also has a notebook full of route descriptions supplied by past climbers.
Check here to make sure your climbing area is open—some are closed to protect nesting peregrine falcons—and remember to bring a pair of binoculars to scout climbing routes from the canyon floor.
If you aren't prepared to tackle the 2,000-foot-high canyon walls, you may want to check out a couple of bouldering sites, both quite close to the south entrance of the park. One huge boulder is 40 yards west of the park entrance; the other is a large slab with a crack, located 0.5 mile north of the entrance.
During the summer, it can be intensely hot on unshaded walls. The best months for climbing are March-May and September-early November.
If watching the climbers at Zion gives you a hankering to scale a wall, the Zion Adventure Company in Springdale (36 Lion Blvd., 435/772-1001, www.zionadventures.com ) runs half-day and day-long climbing clinics for beginning and experienced climbers. Similar offerings are provided by Zion Rock and Mountain Guides (1458 Zion Park Blvd., 435/772-3303, www.zionrockguides.com ). Because no outfitters are permitted to operate inside the park, these classes are held near St. George .
Trail rides on horses and mules leave from the corral near Zion Lodge (435/679-8665) and head down the Virgin River. A one-hour trip ($40) goes to the Court of the Patriarchs , and a half-day ride ($75) follows the Sand Bench Trail . Riders must be at least seven years old for the short ride and 10 for the half-day ride, and they must weigh no more than 220 pounds.