South Mountain Park, just south of Phoenix, is, simply put, home to some of the most brutal and demanding cross-country trails in the country. The National Trail is the crown jewel of the park, stretching 15 miles from the Pima Canyon trailhead in the east to the San Juan Lookout in the west.

Starting at Pima, you warm up with a mellow mile of fireroad before connecting to the National singletrack. From here, it’s a long, slow climb that never bores, due to the numerous ledges, rocks and trials-style hop ups. Yes, you’re going to suffer some (about 3,200 feet of elevation gain by day’s end), but at least you’ll be able to stop, gasp and take in the magnificent views of the Valley. After 14 miles of this sweet torture, you’ll hit the San Juan Lookout. Turn around, drop your saddle and prepare for a blistering descent that’s sure to rattle a few fillings loose. It’s basically all downhill back to Pima.

A word of caution. This is not a trail for beginners. There are plenty of points in the trail (like “the waterfall”) where even experienced riders dismount. You’re also sharing this trail with hikers and equestrians, so keep your eyes peeled for trail traffic, don’t skid, and be courteous. Access to South Mountain’s fantastic trail system hinges on mountain bikers’ good behavior. You can minimize run-ins with hikers by hitting the trail mid-week. Finally, bring lots of water as there are no places on the trail to refill. Temperatures quickly climb into the triple digits out here, even in Spring.

For more info go to http://www.phoenix.gov/PARKS/hiksogud.html