Standing out on his porch in Estes Park one evening this spring, looking out at the continental divide skyline, Tommy Caldwell envisioned a mountain linkup for the ages, a tour of Rocky Mountain National Park’s most stunning peaks. Mount Meeker was the leftmost mountain (or most southerly) that had technical climbing on it, and Notchtop was the rightmost (or most northerly). What if he combined them in one epic climbing-running-hiking-scrambling route? he thought.
The result was a 35-mile long traverse through 17 peaks, with a total of about 20,000 feet of vertical. Caldwell and his partner for the objective, Alex Honnold, dubbed it the Continental Divide Ultimate Linkup (CDUL). Adam Stack, who resupplied the team mid-journey, judged the cumulative number of pitches to be about 65.
Tommy Caldwell started toying with the idea for the CDUL when COVID-19 restrictions were at their most stringent. Climbing outdoors was frowned upon, but Caldwell was still itching to get outside and do something other than just hangboard; running seemed like a good option.
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While running helped Caldwell scratch that itch, he inevitably started thinking about adding climbing into the mix to get a multi-sport mountain adventure.
“I’m not a runner at heart, so kinda wanted to see if I could take what I’d learned from running and the mentality and combine it with climbing,” said Caldwell in an interview with Rock and Ice.
Topher Donahue, a friend of Caldwell’s, had done a smaller version of what became the CDUL about 20 years ago. Caldwell figured it would be possible to expand the idea, including features and climbs that Donahue had not. Adam Stack, with whom Caldwell has climbed since he was a teenager, also helped conceive the plan. Stack had done a similar linkup in Front Range, tagging all the major peaks and climbing formations in the Boulder, Colorado skyline.
When Stack decided the CDUL seemed a bit too intense for him, Caldwell turned to another frequent partner-in-adventure: Alex Honnold. Honnold was psyched. Stack would ultimately stay involved in the mission, resupplying the team mid-Linkup, along with Maury Birdwell.
Although Mount Alice is technically further south than the other peaks in the CDUL, Caldwell and Honnold included it because Alice is possibly the biggest technical wall in Rocky Mountain National Park.
When selecting specific rock climbs, Honnold and Caldwell chose classics over harder or more obscure routes for a variety of reasons. They also tagged all the summits along the way.
“[Alex and I have] done so many linkups in Yosemite and Patagonia and stuff, that it seems like doing the most classic, most buffed out routes is the best way to climb fast in a relatively safe fashion and not have to worry about loose rock as much,” said Caldwell.
They also didn’t want to climb “super hard” because they carried a light rack and a “really tiny rope” so they could move faster.
The CDUL begins with The Flying Buttress on Meeker, a six-pitch 5.9. They then ran up the Casual Route on Longs Peak, a seven-pitch 5.10-. They continued to summit Pagoda, climb The Barb on Spearhead (5.10), Birds of Fire on Chiefshead (5.11a), Central Ramp on Mount Alice (5.8), and Arrowplane on Arrowhead (5.11a).
Honnold and Caldwell then summited McHenry, Powell, Taylor, the Petit Grepon via the South Face (5.8), the Saber via the Southwest Corner (5.10), Sharkstooth via the Northeast Ridge (5.6), Otis, Hallet Peak via Culp-Bossier (5.8+), Flattop, Ptarmigan, and lastly a “cool” 5.9 crack Notchtop (5.9).
The duo set out at 5:20 a.m. and kept moving for about 36 hours, finally stopping around 6:00 p.m. the next evening. Getting through the night was an ordeal that Caldwell called “character building.” Someone they didn’t know particularly well was going to drop off the gear they needed for the night: headlamps, warm clothes, and all their food for that section. But that person got altitude sickness and was unable to perform the drop-off, throwing a wrench into the plan.
Honnold and Caldwell kept moving anyway. Calorie-deprived and dehydrated—they avoided drinking water for fear of it making them colder—they pushed through the dark.
“That night ended up being this bitter wind, probably like in the 20s [factoring in wind chill] all night and we were climbing these mountains in short shorts with our phones jammed under our hats as headlamps,” said Caldwell.
Caldwell tightened his hat over his phone to keep it from falling out, and Honnold held his in his mouth. Although the temperature wasn’t dangerous, it was “uncomfortable”; they kept moving simply to stay warm. Caldwell entered “full-on battle mode” and “did good through the night.” Though Caldwell said Honnold is always “extraordinarily upbeat during character building experiences” like the CDUL, Honnold left the nighttime leading to Caldwell—who grew up with cold Estes Park winters, compared to the Sacramento sun Honnold was raised in.
They managed to call Stack and engineered a small change of plan: Stack was supposed to meet them early morning, but Caldwell asked him to come earlier to make up for the failed drop-off. Stack met them with Chipotle burritos and headlamps.
“He was our hero. We were so in love with Adam Stack at that moment—that was maybe my favorite part [of the Linkup],” Caldwell said.
The route is named the CDUL, and Honnold and Caldwell really did have to cuddle on the traverse. They huddled together as they ate their burritos in their short shorts, making for a “pretty good moment,” said Caldwell.
During the night, Stack bivied with his sleeping-bag liner in a notch they had all dug behind Sharkstooth, which they termed the “sending hole,” from which he took a photo of Honnold and Caldwell on the Sharkstooth summit at sunrise.
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When the sun came up, Caldwell got nauseous. He started puking at one point. Even though he and Honnold had food, he couldn’t hold anything down.
“I’ve never really done something that’s kind of that high of an output for that long and so I think fueling yourself is probably a learned thing. I probably ate too many GUs or something,” Caldwell said.
Honnold, however, could seemingly go forever. “If there were two Alexes we certainly would’ve finished like two or three hours earlier,” Caldwell said.
Other than the drop-off mix-up, the biggest surprise for Caldwell and Honnold was the amount of fourth class scrambling between the peaks. Caldwell had expected more running between features, but he estimated that ultimately there were only about eight miles of actual trails. The sheer amount of scrambling was “pretty time consuming.”
Should someone with more of an ultrarunning mindset choose to repeat the CDUL, there would be several ways to up the ante. Going faster is certainly possible, and doing the route unsupplied would make it more committing, too.
“If you approach this from the perspective of an ultrarunner or something, we were just so JV,” said Caldwell.
“Good little suffer adventure for sure,” said Caldwell.