South Mountain Park, with over 16,000 acres on the southern edge of Phoenix, is the largest city park in the United States. With numerous trails and a close vicinity to town, South Mountain Park is wildly popular! (In fact, most days the trails are extremely busy and parking can be impossible unless you arrive very early.)
The hike begins with a steep 1.5 mile climb up the Mormon Trail. Although several books claim that this portion of the trail is gradual and easy to master, I found it much more challenging than expected. While the trail is shaded during the morning due to its position on the north side of the mountain, the stair-like aspect of the trail left me exhausted and dripping in sweat.
After reaching the summit, the trail opens to a large, flat mesa and intersects with the National Trail. Be forewarned that the National Trail is a very popular biking trail, so you will be yielding to numerous bikers. From the Mormon Trail, you can turn either way on the National Trail; however, my sources recommended continuing to the right since it's slightly easier to traverse Hidden Valley from west to east.
After following the National Trail for about a half-mile, one will see the clearly-marked Hidden Valley Trail. This is where the excitement begins! Almost immediately upon turning, one encounters the highly popular Fat Man's Pass. This 25-foot long crevice between two massive boulders narrows to only 9-inches at one point, so take your pack off and slide through sideways! (If your width happens to exceed 9-inches, you can merely climb over the boulders - which can be done quite easily.) The trail continues through the desert valley for about a half-mile before entering an area of large boulders. Continue along the boulders, but be very careful because the boulders have been worn smooth by years of hikers. Finally, the Hidden Valley Trail finishes with an impressive nature tunnel created by several fallen boulders (pictured above).
Once exiting the tunnel, return to the National Trail and continue left towards the Mormon Trail. Once reaching the Mormon Trail, continue back to the parking lot with wonderful views of Phoenix greeting you the whole way!
To see more pictures of the Mormon Trail and Hidden Valley, click here.