How an Idaho Trail Runner Set a BASE Jumping World Record

This article originally appeared on Outside

In a feat of pure joy and technical precision, Jonathan Cox took a sip of a caramel milkshake and jumped off the renowned Perrine Bridge on the northern edge of Twin Falls, Idaho, on a late-summer afternoon.

The 31-year-old runner-turned-BASE jumper didn't spill a single drop as he sailed down 486 vertical feet into the majestic Snake River Canyon. After touching down at a predetermined landing spot on a dirt path adjacent to the river, he savored more of the milkshake as he removed the harness-rig attached to his deployed parachute and began jogging along a trail that led to the top of the bridge so he could do it all over again.

While Cox's seemingly nonchalant milkshake leap was actually a well-organized jump with a safety-first approach, it was one of the more notable moments of an epic, adrenaline-filled weekend in mid-September. During an almost nonstop flurry of parachute flights that weekend, Cox flew off the massive steel truss arch span 102 times to shatter the world record for most BASE jumps in a 24-hour period.

Jumping Into the Record Books

Cox easily broke the previous record that was set by Denver's Danny Weiland in 2017, when he made 64 jumps off the Perrine Bridge. While Cox's wild feat was grounded in technical flying skills and safety precautions, it was ultimately an astounding endurance undertaking. During that 24-hour period (which began just before sunset on September 15), Cox covered about 20 miles on foot and logged 49,086 feet of vertical gain--considerably more than two of the world's most difficult ultrarunning races, the Ultra-Trail du Mont-Blanc in Chamonix, France (31,200 feet over 106 miles), and the Hardrock 100 (33,200 feet over 102.5 miles) in Silverton, Colorado.

The Perrine Bridge has become a popular destination for BASE jumpers--especially new jumpers just learning the craft--both because of its height over the wide canyon below, but also because it's one of the only bridges in the U.S. where BASE jumping is allowed year-round without a permit.

"It was a pretty wild couple of days," said Cox, a self-employed arborist who began BASE jumping only 18 months ago. "It’s just an awesome feeling to fly the canopy off that bridge. But that's only part of it, because the trail is straight up, and doing that 101 times took a lot out of me."

A Bridge to Somewhere

The Snake River Canyon has held a seminal place in action sports history for nearly 50 years. In 1974, when the Perrine Bridge was being reconstructed from its original 1927 form, the legendary Evel Knievel, the first modern daredevil action sports athlete, attempted to jump the canyon from a massive ramp just east of the bridge site in a custom-built, steam-powered rocket known as the Skycycle X-2.

A design flaw caused the parachute to deploy during the launch, leaving Knievel well short of his intended destination on the other side of the canyon as the rocket crashed at the bottom of the canyon, barely missing the river. The dirt portion of his takeoff ramp still remains about a mile and a half east of the bridge, while a memorial to Knievel is located just below the bridge not far from the trail Cox ran back to the top.

"The ramp is still there and still kind of a big feature in the area," said Jonathan's wife, Olivia Cox, 25, who grew up in Twin Falls. "I run by there almost every day and there’s all these people up on the ramp, exploring, hiking up it, taking photos, checking it out."

BASE Jumping's Outlaw Origins

The early roots of BASE jumping can be traced to Yosemite National Park, where a few early pioneers of the renegade discipline began making jumps off high cliffs of El Capitan in the 1960s and 1970s using slightly modified traditional parachuting equipment. In the late 1980s, as it was still in its infancy, three former U.S. Army paratroopers from Twin Falls had become so intrigued with the idea of parachuting off the Perrine Bridge, they began testing the concept by dropping 55-gallon drums over the edge attached to military parachutes. After several successful trials, they daringly started jumping off the bridge strapped to MC1-1B chutes fixed to a static line tied to the bridge, a technique to ensure the parachute would open immediately.

BASE jumping gained an underground following in the 1980s and 1990s, many municipalities and government agencies prohibited it. However, that only fueled the intrigue and growth as an outlaw activity. Even though it was originally off-limits, the Perrine Bridge became one of the most popular jump sites by the late 1990s, as hundreds of jumpers tested their mettle in renegade style, often at night or by scurrying out of vehicles traveling over the bridge.

Because it was increasingly harder to stop jumpers--and there was a growing belief it would be safer if it was legalized--Idaho passed a law to prohibit cities, counties, and transportation officials from banning BASE jumping from bridges. Since then, the Perrine Bridge has been one of the country's most iconic legal jump sites, along with the New River Gorge Bridge (and its 876-foot vertical drop) in Fayetteville, West Virginia, which is legal to jump from only one day every year.

When Jonathan and Olivia moved to Twin Falls in 2021, he wasn't yet a BASE jumper. But he recalls seeing the bridge for the first time when he was on a family trip more than 20 years ago and always felt compelled to try it someday, especially when he and his wife bought a house about 10 minutes away.

After talking with and observing other local athletes jump, and watching instructional videos on YouTube, Cox made his first jump in April of 2022. He admitted there was some carryover to his daily work in trees, but that's really more akin to rock climbing. He's aware that BASE jumping can be dangerous and deadly--10 people have died BASE jumping from the Perrine Bridge since the early 1990s--but he said training and preparation are of the utmost importance to him, just as it is when handling chainsaws for his day job.

"I didn’t think it was freaky at all. I just thought it was freaking cool," he said. "I just always wanted to try it because I just thought it was the coolest thing. But I never thought I would, mostly because I thought you had to have skydiving experience--that's not the case."

Taking the Leap

Cox participated in a wide range of sports as a kid, including wrestling, soccer, and cross-country. By his early 20s, he started running longer distances to stay fit, and eventually qualified for the Boston Marathon by running the Wasatch Revel Marathon in 2:55:58 in Park City, Utah, in 2021.

He liked the freedom of trail running a lot more, so he didn't register for Boston the following spring and instead chose to run the Beaverhead 55k in Idaho last summer. Although running Boston is still intriguing to him, he's been mostly running trails, and often with Olivia. They both ran the Tough Mugu 25K in Malibu, California, back in July.

"Ever since I’ve known him, he’s always been a big adrenaline junkie, always doing crazy stuff,” said Olivia, who works as a dietician. "BASE jumping is a little bit more out there than some things, but kind of par for the course for what he does--not anything super unexpected. And so when he said he was going to go for the record, I never doubted that he would follow through with it. But the world record was an endurance event, so there was a ton of overlap to running, especially when it comes to fueling."

In the ensuing 14 months after his initial leap, Cox logged more than 1,300 jumps around the West, but most of those have been from the Perrine Bridge. "Once I started jumping, it just became addicting," he admitted. "I’ve just always wanted to push myself. Like, like I just wanna see how far I can actually go."

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Going for the Record

As he got more into the sport, Cox heard about the BASE jumping endurance records set at the bridge. The all-time record for the most BASE jumps in one day is still held by Idaho National Guardsman Dan Schilling, who flew off the Perrine Bridge 201 times in 2006 using a crane to lift him back up to the bridge deck after every jump.

But Cox was more interested in the human-powered records set by Miles Daisher and Danny Weiland from the same site. Those two had traded the 24-hour record back and forth for several years, with Daisher setting an unofficial world record with 63 jumps in 24 hours in 2017, followed by Weiland taking it back a few months later with 64 flights.

After hearing Weiland racked up 29,200 feet of vertical gain--greater than the height of Mount Everest--Cox knew the most difficult part of the record attempt would be to get back up to the top of the bridge. The trail from the landing zone to the base of the bridge is only about 350 meters in length, but it's grudgingly steep. After a short flat section to the base of the climb, the trail ascends 486 feet on a technical, near-vertical trail that requires hand-over-hand scrambling on rocks at certain points. It's the rough equivalent of climbing the stairs of a 45-story building for every lap, only with far more treacherous footing.

Cox initially believed he could go for 70 jumps, then later he thought he could maybe shoot for 80. Last spring, he met Allie McLaughlin, a Hoka-sponsored world champion trail runner who, after several years of skydiving, made her first BASE jump from the Perrine Bridge in March. During one of her several trips to Twin Falls this year, McLaughlin time-trialed the trail to help give Cox a baseline for what was possible and covered the route in 4:36.

"I did a couple hikes with him last spring and I could tell he was really fit, and I knew that was going to be important," said McLaughlin, who has also been intrigued about going for the record. "Then after spending a few days there with him, it was hard not to be a big fan of him. He just brings so much positive energy into it everytime."

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'That's just an Insane Effort'

During his record-setting frenzy, Cox did his first ascent in 4:58 and wound up averaging between five and eight minutes for each of his first 30 ascents. Once back up to the concrete path at the bridge level along Highway 93, he would meet his mother in law, Deanna Sutter, who handed him another newly packed parachute rig and a bike. Cox would then pedal to the middle of the bridge where a friend, Sam Shank, or his brother, Michael, would provide a pilot chute assist--essentially pulling out his pilot chute to facilitate its opening--as he jumped off the bridge once again. All the while, another brother, Timothy, managed logistics and kept count of every jump.

After making a record-breaking 65 jumps in 13 hours and 20 minutes, Cox took a pre-planned break on Saturday morning and got rejuvenated with a 30-minute massage and two saline bags administered through an IV drip. That reinvigorated him to keep going through the evening, even though he admitted to being pretty tired on the last few laps.

Ultimately, it was Cox's solid trail running fitness--and his dedicated crew, which also included Olivia (who managed his fueling and hydration) and about a dozen friends and fellow BASE jumpers--that enabled him to blow away the record. He had some slower hikes during the middle of the night--when he averaged 8 to 12 minutes--and had to fight off fatigue with an 18-minute hike on his 99th climb. (He said he couldn’t have done it without his friend Chantz Lund, who coached him for the world record, ran hundreds of miles with him in training and accompanied him on the final 10 ascents on the trail up to the bridge.)

"When I heard he did 102 jumps, I was just blown away, especially after doing the math and realizing the vert he got," McLaughlin said. "That's just an insane effort. I don't think a lot of people realize how big that is until they realize it's more than UTMB. People have told me I should go for it, and yeah, I want to give it a try, but I have no expectations of beating his numbers. What he did is huge."

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