In Thin Air: Backpacking the Four Pass Loop

Aspen Through the Years: From Toddler Hikes to the Four Pass Loop

Our family’s connection to Aspen runs deep. Thanks to Oren’s work in physics, we’ve had the good fortune to return again and again to this alpine town, nestled in the heart of Colorado’s Rocky Mountains. Whether in winter or summer, Aspen has always delivered—snowy slopes in cold months, and, when the snow melts, a playground of hiking trails, biking routes, and whitewater adventures.

Over the years, we’ve checked off hike after hike, each visit marking a new chapter in our family’s outdoor journey. In the early days, with toddlers in tow, we stuck to short, scenic outings: the shimmering ice caves of the Grottos, the gentle loop at the top of Aspen Mountain, and the always breathtaking stroll around Maroon Lake. But as the kids grew, so did our ambitions. We tackled American Lake and wandered the high country of the Lost Man Trail. By the time they were teenagers, we were hiking straight up Aspen Mountain for a celebratory cup of cocoa and a gondola ride down. Eventually, we even took on the steep and snow-speckled climb to Electric Pass.

By the summer of 2016, Eitan was 18 and hungry for a real challenge. Oren was in Leadville to race the grueling Leadville 100 mountain bike event, leaving Eitan and me with a few days to ourselves in Aspen. We set our sights on the region’s most iconic multi-day hike: the Four Pass Loop. It was time to take on the high Rockies in full.

Backpack Four Pass Loop: Reflections on Maroon Lake

Packing for Peaks: Gear, Permits, and Platelets

Four Pass Loop is no casual stroll. This 26-mile trail circumnavigates the iconic Maroon Bells and climbs up and down four high mountain passes. Once you leave the well-trodden paths around Maroon Lake, there are no facilities—just miles of raw wilderness and whatever you’re strong (or smart) enough to carry on your back. This was a self-sufficient backpacking trip, and for me, it was the first one since high school.

Thankfully, I had an experienced partner. Eitan, then 18, was already a seasoned backpacker and trip leader through his nature and scouting club. His confidence and competence helped me feel prepared, even if I knew I wouldn’t be matching his pace uphill. We packed light but thorough: the essentials, gear for three nights, and food rations for four days. Eitan shouldered the heavier load, but no amount of smart packing could bridge the fitness gap between an 18-year-old and someone thirty years older.

Back in 2016, getting permits was still refreshingly straightforward. We just stopped at the ranger station earlier in the week and filled out a wilderness form. Today, permits for the Four Pass Loop must be reserved in advance via recreation.gov, and are in high demand. We also used the Maroon Lake shuttle to begin our hike—Oren dropped us off early on the morning of July 27, and we were on our way.

The hike is considered difficult not only for its length and terrain but for the sheer altitude. The loop begins at 9,580 feet and crosses four passes—each around12,500 feet. Altitude adds a layer of challenge that’s easy to underestimate. Even strong hikers find themselves winded on these climbs. Without proper acclimatization, hikers risk serious altitude sickness. We gave ourselves nearly a week in Aspen before setting out, spending the days revisiting familiar favorites like American Lake and Ute trail to ease into the thin mountain air.

Backpack Four Pass Loop: Trail map

Backpack Four Pass Loop: Elevation profile

Backpack Four Pass Loop: Eitan and I setting off on the Maroon Creek shuttle

A Classic Start: Setting Out on the Familiar Maroon Lake Trail

Maroon Lake has an irresistible beauty that keeps drawing us back. Nestled in a broad alpine meadow and flanked by towering peaks, its still waters reflect the iconic Maroon Bells—a scene so perfect it feels almost staged. It’s no wonder this spot is one of the most photographed in Colorado, or that it’s been the start of so many of our family hikes.

Over the years, we’ve walked the short loop around the lake again and again, pausing to admire the beaver dam and lodge, always hoping to catch sight of their shy, busy residents. The trail to Crater Lake—relatively short and gentle—became one of our go-to outings as the kids grew. Each time, we’d stop at the same flat rock along the trail for a family photo, with the Maroon Bells perfectly framed in the background. The first time was in 2000, when Eitan was just two years old and already eager to hike on his own two feet.

In this post, I’ve included a few of those photos—snapshots from 2006 and 2009—that capture how our family has grown and changed over the years. The rock is the same, and so is the sense of wonder. Maroon Lake, the Bells, and the surrounding wilderness have remained a constant in our lives.

So of course, Eitan and I stopped again at the rock before beginning our climb. This time, we wore backpacks and wide-brimmed hats instead of fleece jackets and snack-stuffed daypacks. The trees around the lake had grown taller, and the peaks were harder to see—but the ritual was intact, and the adventure was only just beginning.

Four Pass Loop 2016: Eitan (18) and me—returning to the rock

Buckskin Pass hike 2009: The full crew: Eitan (11), Ayelet (14), Oren, and me— more ambitious

Maroon Lake hike 2006: Six years later: Eitan (8), Ayelet (11), and Oren— same trail, longer legs

Maroon Lake hike 2000: First photo on the rock: Eitan (2), Ayelet (5), and Oren—tiny hikers

First Test: Climbing Toward West Maroon Pass

Once past Crater Lake, we left familiar terrain behind. Every step beyond this point was a new adventure. The trail wove through open meadows, climbing gently at first, offering time to warm up our legs and settle into the rhythm of the hike. A few streams crisscrossed the trail, and we carefully picked our way across, trying to keep our boots dry—still early in the day, and no one likes hiking in soggy socks.

After two and a half hours, the mood of the trail shifted. The gradual incline gave way to a series of tight switchbacks, etched into the steep slope leading to West Maroon Pass. It was our first real test—and the thin air made it harder than any map could show. My pace slowed to a crawl. Each step upward felt like pushing through molasses, legs heavy and lungs working overtime. Eitan, meanwhile, climbed like a mountain goat, quickly disappearing from view.

When I finally reached the top, at least fifteen minutes after he did, I found him sitting patiently at the pass, resting and taking in the view. As always with high-altitude hiking, the suffering stopped the moment I did. The struggle faded, replaced by awe. The view from West Maroon Pass was sweeping—wild valleys draped in green and dotted with flowers, mountain ridgelines folding off into the distance. Behind us, the Maroon Bells looked different from this angle, less like the perfect pyramids they appear from Maroon Lake, and more rugged, more real.

It was just past 2pm, and we were feeling strong. At 12,500 feet, West Maroon Pass is the highest point of the loop. If we could do this, we could do the rest. After taking it all in—the shifting views, the wind, the thrill of the climb—we turned downhill, stepping into the wildflower-filled valley ahead and the next stage of our journey.

Backpack Four Pass Loop: Eitan and I at the top of West Maroon Pass

Backpack Four Pass Loop: Walking down the meadow among the wildflowers

High and Cold: The Beauty of Frigid Air Pass

After a short descent into the valley below West Maroon Pass, the trail begins to climb again—another steep push upward. It feels like déjà vu. The terrain echoes the last ascent: tight switchbacks, thinning air, and the same slow, determined pace. Maybe it’s a bit shorter, or maybe we’re just adjusting. Eitan, of course, climbs effortlessly and is once again waiting for me at the top.

Frigid Air Pass lives up to its name. The air is cooler, the light a little softer. It’s now around 4:30 p.m., and clouds drift through the wide sky as we take a short break. We snap some photos of the Maroon Bells from this new perspective, their iconic shape partially hidden from this angle. Then we begin our descent into the next valley.

Movement on the hillside catches our eye—a pair of furry marmots racing down the trail ahead, chasing each other through tufts of alpine grass. We follow quietly, amused by the burst of energy in the stillness.

With two passes behind us, our minds turn to camp. Many hikers stop before West Maroon Pass on the first day, but since we’ve pressed on, we’re on track to complete the loop in three days. As we drop below the tree line, we find a sheltered site nestled among the pines. We set up our tent, rehydrate some freeze-dried dinner, and make tea. The evening air settles around us, and we sit in silence, sipping slowly and watching the last light filter through the forest.

Backpack Four Pass Loop: Commemorating the top of Frigid Air pass

Backpack Four Pass Loop: Furry marmots racing down the trail

The Heart of the Loop: Ascending Trail Rider Pass

Mornings on the trail are quiet. I drink coffee; Eitan drinks tea. Despite my best efforts, he never took to coffee. He likes beer just fine, but coffee? Still a hard no. Somehow, we failed as parents.

Earlier that morning, I had stepped out of the tent in the dark, woken by the call of nature. Above me, the stars were enormous—sharp and impossibly bright. I don’t think I’ve ever seen them so clear. Maybe it was the thin air at 11,000 feet. Maybe it was my half-asleep state. Either way, the scene was magic. I wish I’d lingered longer.

Backpack Four Pass Loop: Starting the second day of the loop

We packed up camp and continued down the valley, feeling strong. A short walk brought us to a cascading little waterfall, tucked among forest and rocks. I tried to take a photo—and promptly slipped. A few scratches were nothing, but my Canon 6D was less lucky. It had fallen, lens-first, into the stream. I shook it out, hoping for the best, but it was done. I was furious with myself. That camera had captured years of family fun. Now, as we hiked from one jaw-dropping scene to the next, I carried it like a guilty weight.

Soon enough, the next climb began: Trail Rider Pass. It was another grueling ascent, this time with a group of men pacing alongside us. One by one, they passed me on the trail—Eitan already far ahead, as usual. When I finally reached the top, lungs aching, Eitan was sitting comfortably. The scent of marijuana hung thick in the thin air. The group was up there, laughing and lighting up. I stared at them, incredulous. “How can you possibly think of putting smoke into your lungs right now?” I gasped. My own lungs were still negotiating for more oxygen.

But the view was worth every breathless step. From the crest of Trail Rider Pass, we got our first look at Snowmass Lake, its deep blue surface tucked into a high basin. That would be our next campsite. We began the descent, walking alongside a tumbling stream and a series of stunning waterfalls. The air was cool and fresh, the trail smooth. For now, the path was kind.

Climbing with Confidence: Tackling Buckskin Pass

Snowmass Lake was stunning, but we didn’t linger. The mosquitoes had claimed it, and no amount of scenery could make up for their relentless attacks. In the morning, we packed quickly and moved on. The trail climbed gently at first, then steepened as we approached our final challenge: Buckskin Pass.

By now, we knew what to expect—the switchbacks, the burn in the legs, the shortness of breath. Physically, it was just as demanding as the earlier ascents, but something had shifted. Mentally, it was easier. We knew we were close to the end. Our bodies had adapted to the altitude and the rhythm of the trail.

At the top, the view took our breath away in the best possible way. We had a sweeping panorama of the Maroon Bells from yet another angle, framed by ridgelines of the high Rockies stretching into the distance. Green slopes dropped away to turquoise alpine lakes below. It was a final reward for all the effort.

We sat for a while, savoring the moment. I floated the idea of extending the hike one more night, heading off-trail toward Willow Lake. But the lure of a hot shower, a good meal, and a soft bed proved stronger. Four passes were enough.

The last stretch was easy. A descent back into familiar terrain, tracing the same valley trail we’d hiked as a family in 2009. Back then, it was just a day hike. No packs. No altitude fatigue. But this time, every step carried the weight—and pride—of the full journey. We had completed the Four Pass Loop, a high-alpine circuit of 26 miles and four stunning passes. And we had done it together.

Backpack Four Pass Loop: Panorama from the top of Buckskin pass, taken in 2009

Full Circle: Returning to Maroon Lake

Once we reach the tree line, we know we’re in the home stretch. The trail leads us into a grove of aspens—those tall, slender trees with silver trunks and eye-like knots that seem to follow you as you walk. Watching them sway gently in the breeze makes you forget, if only for a moment, the weight of your pack and the miles on your legs.

As we descend, landmarks from countless day hikes reappear. The rocky slope alive with the shrill calls of pika. The familiar bend in the trail. And finally, Maroon Lake—shimmering, serene, and framed by the peaks we now know from every angle. It feels like a return to familiar ground, but also a quiet celebration of everything we’ve just accomplished.

There’s a reason the Four Pass Loop is considered the ultimate Rocky Mountain hike. It’s the perfect blend of wild beauty and personal challenge. It’s remote enough to feel like a true backcountry adventure, but accessible enough to complete in just a few days. We chose three, but it can be stretched to five with time for side hikes, swimming holes, or simply more quiet mornings by alpine lakes.

For me, this hike was a return to backpacking after a decades-long break. For Eitan, it was another step forward in the outdoor life he’s been building for years. And for both of us, it was a shared accomplishment—tough, stunning, exhausting, and unforgettable.

We’ll be back in Aspen later this fall, and part of me is already wondering: should I hike the loop again? Maybe. But no matter what, this journey—this loop—has already become a full circle in more ways than one.

Backpack Four Pass Loop: Walking in the Aspen grove

Backpack Four Pass Loop: Aspen trees, silver trunks with eye-like knots

Resources

Maroon Bells-Snowmass Wilderness Overnight Permits

Maroon Creek bus