More than half of the climbers who try to summit Mount Rainier don’t make it. And as a guide on the state’s tallest mountain, I feel them fail.

As I trudge slowly up the mountain in the predawn hours, the rope tied around my waist and tethered to my clients will go taut until I’m leaning forward like a husky hauling a dogsled. I’ll hear the rhythmic crunch of crampons slow down. When it slows enough I’ll stop climbing, bury my ice axe in the slope, and turn to see their bodies slumped into the snow. Their breath steams in tight clouds in the beam of my headlamp. Their faces are red, sometimes desperate. They know and I know that it’s time to turn around. We call it spinning.

In 2010, of the 10,643 climbers who attempted Mount Rainier, 4,920 reached the 14,410-foot summit. That’s just 46 percent of the people who trained for months and spent hundreds of dollars on ice axes, plane tickets, and lightweight titanium sporks. Almost every guided climb includes at least one climber—and often several—who turns around before reaching the summit. During my first five-month season as a Rainier guide, in 2009, I spun with clients at least 20 times.

Ten years ago, guided climbers didn’t spin. They were left behind while the rest of group ascended, secured inside a sleeping bag and anchored to the snow or rock, and forced to wait for when everyone else headed back down. The practice was unofficially known as “bag it and tag it.” Guides would even remove a boot from the halting hiker if it looked like he or she would foolishly try to head down the dangerous glacier alone.

Since the mid-2000s, the National Park Service has specified that guided clients may not be left without a guide above Camp Muir, requiring greater client-to-guide ratios so everyone has an escort. On any given day there are as many as 50 guides on the mountain for some 150 clients.

People turn around for all kinds of reasons. Sometimes the whole group turns back because the weather is too awful, the avalanche conditions too dangerous, or the route simply too crevasse riddled. There are physical injuries like twisted ankles or sore knees. And there are the oddball cases, like the man dressed in a football uniform who gorged on energy gels and vomited in fluorescent colors for three days. 

But more often than not, the reasons for spinning are psychological—something snaps deep in the chest of able-bodied climbers as we hike into the unknown. They blame the altitude, or the cold, or their gloves, or their fellow climbers, for walking too fast or too slow. They even blame the guide. Usually they admit that they’re licked and beg to descend; when they don’t, we’re trained to be kind but very firm. Behind the disappointment I can always see the relief in their eyes. 

Climbing Mount Rainier is not a passing whim; at some point, every one of those climbers wanted the summit, badly. It’s not uncommon to meet clients who have lost 50 pounds in preparation or traversed half the globe to get to Paradise. Most climbers are successful, driven, strong people—doctors, Ironman triathletes, CEOs of Fortune 500 companies. To some, not summiting feels like failure. On the way down, groups follow the guide like tired goslings and the summiteers chatter with cheerful exhaustion. But the spinners are silent, curling into themselves, privately processing shame or disappointment or merely fatigue. It’s hard to watch.

But the shame, if there is any, may be fleeting. In 2008, the Mountaineering Federation of Iran conducted a study on the impact of a single mountaineering expedition on self-esteem. The statistical majority of all participating climbers experienced a lasting increase in self-worth, but “self-esteem in the participants that did not reach the [summit of] the peak improved more than that of the others.”

After a few years on the mountain, that finding doesn’t surprise me. People are drawn to challenges like mountaineering to find their own limits. While some can bag huge peaks without ever pushing their physical or emotional capacities, others reach their limit 15 feet above the Paradise parking lot. For the people who spin, maybe the line was physical, or it was a fear of heights or the unknown. Whatever edges they discovered, they have a better idea of their own inner workings. Some will return a half-dozen times before finally summiting, while others toss their gear on eBay and shudder at the memories.

I used to ache for words to comfort the spinners, but now I let them work through their own decompression. When we’re high on the mountain and I feel that tug on the rope behind me, I know that they’ll need a minute to sit. It’s important to breathe in the sunrise before starting the long, slow descent. There’s a climbing adage that says “The summit is for the ego, the journey is for the soul.”