CHARLES LIU immigrated to the United States from China in 1980 and settled in a suburb of Phoenix with his extended family. During his formative years at Arizona State University, Charles grew increasingly fond of the Grand Canyon State's diverse outdoor offerings. Hiking quickly became his passion; in particular, he adopted a keen preference for challenging day hikes and alpine mountaineering. An avid outdoorsman and active member of several hiking clubs and creator of his own hiking group, Charles has led countless hikes over the years, including annual treks to the depths of the Grand Canyon and to the 12,633-foot summit of Humphreys Peak, Arizona's highest point.

An engineer by trade, Charles spends much of his spare time hiking, photographing, and writing about trails in and around Phoenix. He can often be found racing up Camelback Mountain after work, relieving stress from a high-tech career, or traipsing through the Superstition Wilderness on weekends.

Aptly nicknamed "Mad Hiker," Charles finds fulfillment in tough hiking challenges. He has recently conquered Mount Whitney in California, Mount Rainier in Washington, and all of Colorado's 58 "fourteeners." He has also climbed challenging peaks worldwide, including Kilimanjaro, Aconcagua, and Elbrus. Charles's extensive hiking experience, attention to detail, and passion for hiking make him an ideal trail guide for the 60 Hikes Within 60 Miles series.

To contact Charles with comments or suggestions, visit his website, madhiker.org/6060.