"DO NOT FALL," shouted Garrett Stevens, a guide with Rainier Mountaineering Incorporated (RMI).
It was 2:30 in the morning, and our four-man team was traversing Mount Rainier's Ingraham Glacier. In the moonlight, a monstrous crevasse was visible about 50 yards down the icy 30-degree slope below us. The thin snow trail, packed and then eroded by previous teams, narrowed to a boot-width ledge.
If it weren't for the crevasse, crossing this section would be like walking along a curb. But tied to a string of groggy guys wearing snag-prone crampons in the middle of the night, above an ice luge to an abyss, it was not the time to be wishing I'd trained a little harder for this climb.
Not that any part of a Rainier climb is friendly to couch potatoes. At 14,410 feet, it's the fifth-tallest peak in the lower 48 and the most heavily glaciated, rising almost two vertical miles above the surrounding terrain and riddled with deep crevasses. The weather can go from mild to nightmarish in a matter of hours, and the 9,000-foot altitude difference between the base village and summit makes the upper slopes seem twice as steep. It's no wonder the mountain is considered a classic stepping stone to the Himalayas.
Which is why it's so surprising that you can safely join a Rainier expedition without any real technical climbing skills. In fact, the three guiding services on the mountain actually welcome beginners. As I found out on my climb with RMI, they handle everything: teaching and honing essential skills, picking the route, organizing gear and food, analyzing weather and snowpack, and making the key judgment calls, like deciding when a wheezing team member needs to head back to camp. All you have to do is show up in top shape.
Any climbing team moves only as fast as the slowest member, but this factor is magnified on a guided expedition, when you're roped up with three strangers (with other teams lined up behind and in front of you), climbing and descending almost two vertical miles in less than 30 hours. Sure, a reasonably fit person with a good guide can suffer their way up and down Rainier. But that's not fun—and it's not fair to your teammates. Your goal isn't just to survive as dead weight. As our leader, RMI's co-owner and 25-year veteran guide Peter Whittaker, said during our first orientation, "you need to ask yourself one question: Am I an asset to my team or a liability?"
The best way to make sure you're the former is to start building fitness specific to mountaineering about six months before the climb. It takes that long to develop the kind of lower-body, core, and aerobic conditioning to make you a hiking and pack-carrying machine. (Plus you need to reserve a spot with a guiding service that far in advance; by the end of January, prime-season trips are often booked out.)
Thankfully, everyone on my team had shown up fit and ready to climb. On summit morning, after quickly traversing the Ingraham Glacier, we scraped our way up the chossy volcanic rubble of Disappointment Cleaver in the dark, then weaved through a dozen crevasses as the rising sun turned the glacier amber and pink. As we closed in on the rim of the almost perfectly circular crater on top, we blew past team after struggling team. By 7 A.M., we were fist-bumping and mugging for photos on the summit, feeling strong enough to savor the moment, wishing there was some way to go even higher.