An explosive investigation published this week by National Geographic alleges that Portland endurance athlete Colin O'Brady embellished aspects of his celebrated history-making solo trek across Antarctica.

In a lengthy feature published Sunday, the magazine spoke to several polar explorers—including some of his mentors—who claim O'Brady misrepresented the facts of his journey, including the difficulty of the route he took, his claim that it was "unassisted," and the notion that he was the first to accomplish the feat.

In 2018, the 34-year-old O'Brady—the son of businesswoman and former Portland mayoral candidate Eileen Brady—made headlines by becoming the first person to cross Antarctica alone and without any assistance beyond his own power.

The feat earned him a book deal, television appearances, speaking engagements that can command up to $50,000, and a whole day in Portland named in his honor—plus a spot on the cover of this newspaper.

But in the National Geographic piece, experts say O'Brady has "distorted the truth in pursuit of fame."

"This wasn't some Last Great Polar Journey," Eric Philips, president of the International Polar Guides Association, tells the magazine. "Rather, it was a truncated route that was a first in only a very limited way."

National Geographic spoke to O'Brady three times in the course of their reporting, who classified the claims against him as "armchair criticism." He eventually stopped responding to the magazine.

This morning, O'Brady issued a response on Instagram, writing that he was "stunned" by the article.

"I'm not sure how or why they got the facts so twisted around," he wrote, "but I assure you the article is full of inaccuracies."

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TRUTH AND TRANSPARENCY - A couple of days ago I was stunned to see a confusing article in Nat Geo about my expeditions. I’m not sure how or why they got the facts so twisted around, but I assure you the article is full of inaccuracies. Here’s just one example—the article inaccurately states “O’Brady claims to be the first person to ski alone and unsupported across Antarctica . . .” It’s as if the journalist may not have read my book. The photo above is from page 49 of The Impossible First, where I acknowledge and compliment one of the most pioneering Antarctic projects of all time. I write, “The Norwegian adventurer Borge Ousland in many ways defined the terrain of astonishing modern Antarctic feats, becoming the first person to cross Antarctica solo when he traveled eighteen hundred miles alone in sixty-three days from late 1996 to early 1997. Not only did he cross the entire landmass of Antarctica, but he also crossed the full Ronne and Ross Ice Shelves from the ocean's edge. Ousland’s expedition, which had deeply inspired me, was unsupported in that he’d hauled all his food and fuel with no resupplies . . .” Ousland used a parawing (kite) and traveled much farther than I did. I was completely human powered, crossing just the landmass. Apples and oranges. I look forward to continuing to express my humility, gratitude, and appreciation for those who came before me, and I’ll be cheering from the front row all future expeditions in Antarctica that will inevitably continue to push the boundaries. You all know that a big part of how I live revolves around transparency—sharing my journeys and my ups and downs with the world. It’s why I keep my GPS live throughout every expedition so you can see where I am and where I’ve been. So, I’m going to keep following that practice with this issue. I’m putting together a letter to the Nat Geo editor providing them with the supporting materials they can use to correct the record. Because there are a number of errors, it’s going to take me a few days to finish it. When I do I’ll post a copy of the letter on my website.

A post shared by Colin O'Brady (@colinobrady) on

O'Brady is the scheduled guest for a taping of the radio show Live Wire tonight at Alberta Rose Theater.

The National Geographic story scrutinizes O'Brady's claim that he achieved "the impossible," and did it first. (The title of O'Brady's book, published last month, is The Impossible First.) Several experts quoted in the piece say the credit for the first unassisted crossing of Antartica belongs to Norwegian Borge Ousland, who completed the trip in 1997, skiing 1,864 miles in 64 days.

The only discrepancy is that Ousland occasionally utilized "a small kitelike device to boost his speed when the wind was just right." It wasn't until 2007 that the website Adventure Stats codified the rules for polar expeditions, determining that a crossing could only count as "unassisted" if "nothing but your own muscle-power" was used.

Furthermore, O'Brady's journey only accounted for 932 miles, significantly less than Ousland's—the difference owing to the fact that the continent of Antartica is essentially a massive, shifting block of ice, whose beginning and end points are a matter of debate.

On Instagram, O'Brady points out that he acknowledged Ousland's accomplishment in his book, and that it served as inspiration for his own journey.

But the article also points out instances in which O'Brady appears to have exaggerated specific details of his trek.

For instance, O'Brady says he crossed through several "no-rescue zones," where he was told by rescue crews, "If you call for help in here, you won't get it." Antarctica Logistics and Expeditions, an organization that assists adventurers in planning trips across remote part of the continent, denies making such a claim.

Another expert says rescue in those areas, in good conditions, is "as benign as requesting an Uber."

In fact, for the final leg of the journey, O'Brady followed "a graded and flagged vehicle route used frequently by wealthy tourists" known as the South Pole Traverse to help avoid treacherous stretches—something he downplays in his book.

"IMHO skiing on a tractor road is a bigger 'aid' than a kite," American climber Conrad Anker tweeted.

The article also paints O'Brady as a bully. During a prepatory group hike across Greenland, O'Brady is described as being "manipulating" and "denigrating" to the other members of his party.

"[W]e really suffered," a German neuroscientist told the magazine, in an account confirmed by others in the group. "Colin had his own agenda and can be very pushy."

On Instagram, O'Brady wrote that he plans to put together a letter to send to National Geographic, "providing them with the supporting materials they can use to correct the record." He wrote that he will publish the letter on his website when it is completed.

Last month, O'Brady completed another mission: crossing the treacherous Drake Passage with no mechanical assistance, which was filmed by Discovery for an upcoming documentary.

Read the full National Geographic article here.