What do you do when your three-year-old son shimmies up the outside of a second-floor banister, propels himself onto a grandfather clock, and then greets you with an ear-to-ear grin? If you're Mark Miller, a member for the past five years, you might just chalk it off to kids being kids. But for Mark, this fearless behavior wasn't surprising at all – in fact, he fully expected that personality trait to carry over into Evan's adult life, manifesting in mountain climbing, skydiving, rock climbing and other adrenaline-pumping athletic pursuits.

That fearless toddler grew up to become Evan Miller, now 30, who recently accomplished what most of us can only dream – standing atop Mount Everest, the world's highest peak at 29,032 feet (or about 5.5 miles towards the heavens.) But this wasn't just any climb; Evan followed it up by immediately conquering Lhotse, the fourth-highest mountain in the world, making him one of the few climbers to summit both peaks back-to-back in a single expedition.

The path to Everest actually began thirty years ago when Mark read "My Old Man and the Sea" – not Hemingway's classic, but a true story about a father and son who built a sailboat and sailed around South America to repair their relationship. Inspired by this tale, Mark sought his own powerful bonding experience with his father, Jim Miller, and they traveled to Tanzania, Africa to climb Mount Kilimanjaro at 19,341 feet.

Twenty years later, seeking a similar shared experience with his own son, Mark and then-19-year-old Evan embarked on a father-son bonding trip to Ecuador, where they climbed active volcanoes together. That's where Evan truly caught the climbing bug.

"I realized how fun this sport actually is," Evan explains. "How much goes into it, the logistics, the complexity of getting a whole expedition together, training for it, being in good enough physical and mental shape to actually climb the thing."

Over the past ten years, Evan has been climbing ever more challenging and higher mountains. Two years ago, father and son tackled Mount Aconcagua, the tallest mountain in North and South America. Mark made it to 20,000 feet while Evan summited at 22,837 feet.

Today, Evan spends four to six months each year climbing around the world – from Nepal and Pakistan to France and Scotland. He now has over twenty-five mountains under his belt, with five of them being 8,000-meter peaks – among the fourteen tallest mountains on the planet. He holds the American record for climbing Gasherbrum I and II in Pakistan, making him the youngest American to summit those peaks.

But don't expect Evan to boast about his accomplishments. "He's pretty humble about what he does," Mark notes. "He's considered a world-class high-altitude climber now, but you'd never know it talking to him."

This past spring, the Millers embarked on their most ambitious adventure yet. They flew to Kathmandu, trekked together for 11 days through the spectacular Himalayas to Everest Base Camp, and shared what Mark describes as "Nat Geo moments" at every turn.

"Every vista, every time you turn, it's just spectacular," Mark explains. "The Nepalese people are incredibly kind, warm, sincere people. We slept in tea houses with no heat, getting higher and higher above the earth each day."

The highlight of Mark's journey came at Kala Patthar, an 18,500-foot peak famous for its sunrise view of Everest. "We climbed up at night and were there for sunrise over Everest," he remembers. "That was a moment to share with Evan. But to put it in perspective – when I was standing at 18,500 feet, Evan still had another two miles up into the sky to reach Everest's summit."

At base camp, built on a moving glacier that shifts three to four feet daily, Mark experienced the raw power of the mountain. "You hear the glacier popping and moving. It's alive, this thing," he recalls. "We slept in a tent, and it snowed overnight. You're right at the base of Everest – it's very real."

After experiencing base camp together, Mark departed, leaving Evan to face the mountain's most challenging sections with his Sherpa, Nyima Gyalu. "We joked that being at base camp and then him going on from there was really like me just dropping him off at the bus stop in kindergarten," Mark joked.

The climbing world has become increasingly commercialized – this season saw nearly 600 climbers attempting Everest and neighboring Lhotse, creating dangerous traffic jams in what climbers call "the death zone" above 26,000 feet.

"Your body can't physically survive up there for more than 48 hours without supplementary oxygen," Evan explains matter-of-factly. "Your body is literally dying once you get to that altitude."

Evan's strategy was patience. Rather than joining the initial rush, he waited for a less crowded weather window. The summit push took three and a half days, during which Mark tracked his son's progress via satellite using a device called InReach – a tiny satellite transceiver that Evan carried with him. Each day involved 6-8 hours of climbing around massive crevasses and other obstacles to reach his destination.

"There were two times where he didn't move for four or five hours," Mark recalls. "I was tracking him, and one time it showed him right next to a crevasse. What are you naturally going to think?" Mark had faith in his well-trained and prepared son, but there was no getting around the fact that Everest doesn't offer safety nets or, in video game terms, a second chance if you fail the first time.

What sets Evan apart isn't just his climbing ability – it's his character. Unlike many climbers who use Sherpas as pack animals, Evan carries his own 50-pound pack, earning respect throughout the Sherpa community. Last year, he saved his snow-blind Sherpa's life during a 14-hour rescue on Manaslu, the world's eighth-highest peak.

"I took my hands and put them in front of his face, and he could just see a shadow," Evan recalls. "I radioed down to base camp, and they told me to leave him. I said it's not gonna happen – he will die."

For 14 hours, Evan assisted his Sherpa down the mountain, tethered together through treacherous terrain. "He was lucky that he had me, and that I had the experience to actually do something about the situation." Once again, showing the character of this young man who risked his own safety for another human being when many would have just moved along.

Mark admits the waiting was the hardest part. "In the very earliest days, I thought reaching the summit was what it was all about. But you're only halfway done when you get to the top – getting down is really the critical thing."

His relief was tempered by knowing Evan still had Lhotse to climb. "I wasn't totally happy until I knew he was back down at base camp from both mountains."

For fellow members considering their own mountaineering adventures, Evan's advice is straightforward: start small, get proper training, and work your way up gradually. "It's the same as with a job – you work your way up in a company. It's not a process to rush."

Evan is currently in the process of attaining his guide certification and welcomes inquiries from anyone interested in getting into the sport or planning a trek somewhere around the world. "I would be happy to provide advice and insight to any of your readers," he says. "Please don't hesitate to send an inquiry!" He can be reached at evanmillerclimbing@gmail.com.

As for that fearless three-year-old who once terrified his father by leaping onto furniture? He's still climbing, still pushing boundaries, and still making his dad both proud and nervous. Some things, thankfully, never change.