Electricity was buzzing all around him just below 14,000 feet on Mount Lindsey in the Sangre de Cristo Mountains of Colorado – it was a tale-tell sign lightning was about to strike. But Denver’s Andrew Hamilton, 40, was driven by his goal to set a new speed record of climbing all 58 of Colorado’s 14,000-foot peaks.

As a boy, Hamilton would summer in Cortez, Colorado, near the La Plata Mountains, where his step-dad introduced him to the mountains. In college, he’d summer as a raft guide in Buena Vista, where the collegiate peaks stared him down. Then came “Colorado’s Fourteeners,” by Gerry Roach, with a chapter on speed climbing. The record was 16 days. “I remember thinking, ‘I could do 16 days.’ I just got it in my head.”

More records were set, then in 1999 Hamilton bagged 55 summits in 13 days, 22 hours, 48 minutes.

In the summer of 2000, Teddy “Cave Dog” Keizer climbed all 58 peaks in 10:20:26. His record held for 15 years.

The Rules: The clock starts at 3,000 feet within the summit; summits could be linked but climbers must descend 3,000 feet after the last one; no aid is allowed while climbing; climbers can be followed, but not led; and you must alert the previous record-holder of your attempt.

Climbers began using the Internet, social media and tracking devices to lay out their plans and post updates.

In the time since his own record, Hamilton began adventure racing.“Over the years I began to believe this theory that you don’t need a whole lot of sleep.”

Hamilton’s 2014 attempt with a one-man support crew took a turn with an injury. “We spent the night shivering on a ledge on South Maroon Bell.”

For 2015 he gathered a large crew to help with everything, from driving to food, to packing and repacking, to first aid. “Literally, the only thing they weren’t doing was the hiking,” he said.

His final time: Nine days, 21 hours, 51 minutes.