It's time to get out of that rock gym and take your calloused fingertips to the Valley's best granite playground — the McDowell Mountains. C'mon, it's not too hot! Hundreds of rock-climbing routes populate thousands of acres of the McDowell Sonoran Preserve, some accessible by specially marked trails for climbers. The Arizona Mountaineering Club identifies 18 distinct locations, each with multiple climbing routes. None of the routes is taller than 150 feet, but don't let that discourage you. It would take years to bag every route in the McDowells, and the variety and easy access is well worth the trip. Sven Slab, for instance, sports at least 25 climbs ranging from 5.4 to 5.10c, meaning there's something there for everyone. Our favorites include Sven Slab, Morrell's Wall, Gardner's Wall, and Tom's Thumb. But other spots like Granite Ballroom, Hog Heaven, Goat Hill, and Thrasher offer terrific short climbs and bouldering options. Most of the climbing areas are within a couple of miles of the Tom's Thumb trailhead parking lot. But don't expect the climbing trails to be as casual as the trails used by hikers. Be extra-cautious here to avoid trouble. Scrambling and minor boulder moves are required to get to some spots. Plus, some areas are relatively remote, even when you can see houses far below. While on your belay ledge, keep an eye — and camera — out for sightings of wild horses, javelinas, and other desert wildlife.