A look back at the life, and disappearance, of the ultrarunner known as “Caballo Blanco,” who gained fame from the 2009 best-selling book Born to Run:

“Ray Molina, 44, had not learned of the disappearance until Friday. He rushed to the Gila in his beat-up 1979 Mercedes with two friends, Jessica Haines and Dean Bannon. They were agreeable to joining the organized search. But by 10 on Saturday morning, they were among a handful yet to be assigned to a team.

“The hell with this, Molina concluded. He and his friends lightened their backpacks of unnecessary gear and went off on their own, simply walking a short distance down the access road, crossing the Gila River and scurrying into the nearest arroyo.

“This strategy, while not entirely random, was hardly well conceived. They were assisted only by a folded-up map and their own instincts and whims.

“They rambled and they ran and they climbed. They called out, ‘Caballo!’”