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<strong>“Remind me not to do this again next year,”</strong> Dave Mackey said with an uncharacteristic hint of despair as he neared the top of Sugarloaf Mountain.

It was about 8 a.m. on the morning of August 18, 2018, and Mackey was 17 miles into the Leadville Trail 100, the classic 100-mile “Race Across the Sky” in the heart of Colorado’s Rocky Mountains. But he was also one of about 70 runners in the 715-runner field who was also six weeks into the grueling, summer-long Leadman competition—a series of six ultra-distance endurance events staged in the high-altitude environs of Leadville, Colorado—so he was feeling a bit ragged and tired.

Not only was the 48-year-old physician assistant from Boulder battling fatigue from the series’ 100-mile mountain-bike race and 10K run the weekend before, but he was also dealing with chafing from his prosthetic leg. As a veteran endurance stalwart, Mackey knew what it would take to get through a hard 100-mile run. But as a relatively new amputee, he knew he would likely have a long, grueling day and night still ahead of him if he was going to finish and earn the celebrated Leadman pick-axe finisher’s trophy for the second time in four years.

At his lowest point, Dave Mackey thought he’d never run again. At least not fast or with any purpose. And you couldn’t have blamed him for thinking that way. For a super-motivated, always-optimistic, tough-as-nails guy who relished tackling the hardest trails, the steepest mountains and the most grueling ultra-distance races with aplomb, it was hard to be very hopeful. It took 13 surgeries to repair his badly injured left leg that had left him with a debilitating limp and no sign of full recovery.

So, the two-time U.S. ultrarunner of the year was only being realistic when he decided, 17 months after a horrific trail running accident in 2015, to voluntarily have part of the leg amputated.

When it came down to it, he was happy just to be alive and blessed to have a happy, healthy family—wife, Ellen, daughter, Ava, then 8, and son, Connor, then 6—so he knew no matter what adjustments lay ahead for him, everything would be OK. He just wanted to get back to doing what he loved to do most—running up and down mountain trails—and he knew opting for amputation would probably present his best path to that, even if it meant the difficult process of learning to run again with a prosthetic leg.

Putting in the hard work to overcome difficult challenges is what Mackey has done all of his life. For nearly 20 years, he had humbly and quietly established himself as one the top adventure athletes in the United States, excelling in ultra-distance trail running, rock climbing and multi-sport adventure racing.

His body of work included winning the Montrail Ultra Cup (in 2004 and 2011), trail-running national championships for 50K, 50-mile and 100K distances, earning podium finishes in international adventure races, breaking records scrambling up and down Boulder’s iconic Flatirons and setting the (since broken) Rim-to-Rim-to-Rim record for running 42 miles across the Grand Canyon and back. Just six weeks before his accident, he placed 12th in the harrowing six-day Marathon des Sables across the Sahara Desert in Morocco.

He accomplished it all with a relentless work ethic and a deep toolbox of athletic skills, most notably a huge aerobic engine, amazing physical strength, uncanny body control on off-camber terrain and, perhaps his biggest athletic gift, a calm but tenacious demeanor in the face of adversity.

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