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An Alaskan athlete’s 65K roundtrip run in the Grand Canyon

Lars Arneson set the fastest known time on a 40-mile route from one side of the Grand Canyon to the other and then back again

Photo by: Grand Canyon National Park

Alaskan ultrarunner Lars Arneson recently completed a 65K run in the Grand Canyon, breaking the fastest known time (FKT) for running from one side, down into the canyon, up the other side and back again to the start. The route, known as the Grand Canyon R2R2R (rim to rim to rim), took Arneson six hours, 38 minutes, and he beat the previous FKT by a quarter of an hour. He ran at an impressive and even pace, and according to his post-run report on fastestknowntime.com, he made it to the halfway turnaround in three hours, 15 minutes before making the return trip and grabbing the official R2R2R FKT. 

As Arneson told the Anchorage Daily News (ADN), he had originally planned to travel from Alaska to Arizona to get some heat and escape the start of winter up north. Like most runners, though, he didn’t get to compete much this year, so he decided to put his fitness to the test with the R2R2R. 

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“I had a really big summer of training and no races,” he told the ADN, “and I felt like this was a good opportunity to see how I stack up with some of the best runners in the country and give myself an opportunity to put those months of training to use.” Arneson decided to go for the route’s unsupported FKT, which meant he had to carry all of his own gear, food and water. The supported R2R2R FKT belongs to Jim Walmsley, who ran the 65K route in a mind-boggling five hours, 55 minutes in 2016 (about 5:30-per-kilometre pace). The unsupported FKT was a much more achievable (but still very tough) time to beat of six hours, 53 minutes, which Dakota Jones set in 2011. 


Arneson started his run on the north rim of the canyon, early in the morning on November 20, when the temperature was just above freezing. He writes that he got a bit “turned around” at one point, but he sorted himself out and still managed to get to the south rim in decent time. His way back was much more difficult, and his legs took a beating in his descent after turning around. In total, he climbed 3,400m throughout the run, which he said really took a toll on him. 

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“I’m hobbling pretty well today,” he told the ADN the day after his run. “I’m pretty sure I’m going to lose both of my big toenails. My calves are quite painful and I have a few blisters on my right foot.” Despite dealing with that fatigue, the wear on his joints and muscles, and running out of water in the final few kilometres, Arneson managed to make it back to the Grand Canyon’s north rim with plenty of time to spare, smashing the FKT.