Jerry Schad had a simple explanation for his ability to quickly experience every mile he wrote about in his guidebooks, which helped expand hiking opportunities in Southern California: “I run through the boring parts and walk through the interesting ones.”

His “Afoot and Afield in San Diego County,” first published in 1986, is regarded as the pre-eminent guide to the region’s trails. He followed it with two other well-regarded “Afoot and Afield” books, on Orange County and then Los Angeles County.

“Jerry took San Diego County and created a whole universe for hikers,” said John McKinney, a former Los Angeles Times hiking columnist. “All of his books are great, but his heart was in San Diego, where his home was. He just really made San Diego sing, virtually covering every pathway there.”

Schad, who also was a professor of physical science and astronomy at San Diego Mesa College, died of kidney cancer Thursday at his home in San Diego, said his wife, Peg Reiter. He was 61.

Biking at Berkeley

An outdoors enthusiast since he discovered cycling as a University of California, Berkeley student in the late 1960s, Schad was a former adventure runner who viewed his devotion to hiking as less compulsive than previous pursuits.

He once rode his bicycle from San Jose to Los Angeles in under 22 hours and ran across the Grand Canyon, rim to rim, in under four hours. Yet to research the dozens of hikes in “Afar and Afield in Los Angeles County,” Schad reported walking more than 1,000 miles.

“If you read a Jerry Schad book, you could be certain that everything was accurate,” said John Robinson, author of the classic guidebook “Trails of the Angeles.” “He was a very outstanding hiker and a great mapper.”

Soon after moving to San Diego in 1972, Schad noticed a book on Northern California cycling and decided to write its counterpart, “50 Southern California Bicycle Trips,” published in 1975.

It was the first of his 16 books, which mainly focused on outdoor recreation. His hiking guides were inevitably praised for their clarity and conciseness — and for delving into the history of an area.

They included “Backcountry Roads and Trails, San Diego” (1976), “101 Hikes in Southern California” (1996) and “50 Best Short Hikes, San Diego,” which will be released later this year by Wilderness Press. He worked on his final book until a few weeks ago.

“He was always deeply thoughtful, extremely intelligent and knowledgeable,” said Susan Haynes, the book’s content editor. “And he always had such a wonderful laugh.”

From 1990 to 1992, Schad penned a monthly hiking column for the San Diego edition of the Los Angeles Times, devoting his final column to Anza-Borrego Desert State Park.

Hiking photography

“He encouraged people to take a hike in almost every kind of terrain there is in San Diego County,” McKinney said. “And he did a great job in particular sleuthing out hikes in Anza-Borrego state park and its 600,000 acres. He literally put that place on the map.”

Schad also was a gifted photographer, “the best among hiking writers,” McKinney said. “It’s not easy to capture the essence of a hike in action, and he did that really, really well.”

Since 1993, Schad had written his “Roam-O-Rama” column for the San Diego Reader. The first one described “a wild and lonely campsite in the Anza-Borrego Desert called Mortero Palms” and the last, in July, acknowledged his illness before urging readers to “just get out there!”

A fifth-generation Californian, Gerald Louis Schad was born Nov. 3, 1949, in San Jose, a descendant of settlers who moved to Northern California during the Gold Rush.

About 18 months ago, he went on a first-date hike with Reiter in Balboa Park. They were married in March, four days after he was diagnosed with terminal cancer. The spot where the couple first met — the park’s Trail 43 — will be known as the Jerry Schad Memorial Trail.