No blind person had stood on top of Mt. Whitney before. Ever. I planned my PCT thru-hike so my two partners and I would be there on June 27, Helen Keller’s birthday (we made better time and went through six days early). We wanted to start from Guitar Lake, but we heard that’s where the snowline was and we didn’t want to sleep on ice. So we began at a camp a mile past the Crabtree Ranger Station, following the John Muir Trail for five miles and 3,700 vertical feet to the summit—and the same back down.

This isn’t the normal summit slog from Whitney Portal. We would climb the peak on the backside’s deep wilderness, and rise steeply above treeline and the half-dozen tarns that pool below this scree-laced tower. The guidebooks all rave about the scenery—a great stretch of serrated, gray-brown peaks linked together like teeth on a giant chain saw—but I experience it in a different way.

When I hike, I navigate by passive echolocation, like a bat, listening to the sounds I make come back to me. Whether it’s us talking or rocks tumbling nearby, it gives me a signature, and I have a basic idea of what my surroundings will be like—whether it’s open or there’s a cliff.

Normally, I tune in on the footfalls of the hiker in front of me and put my foot exactly where he did. But when we got to Guitar Lake, we hit snow, and in such an open bowl, the sound carries. I could tell it was huge, but it was hard to judge exactly where to step. Halfway up the face, the slope steepened to 40 degrees and I knew it. My feet are so sensitive now that I can feel the paint lines on the sides of the roads through my boots, and I know when the snowpack is unstable.

It was dicey, but I took it slowly until the slope flattened over the last cornice. The sound was incredible. It was like a vacuum, and I knew there was nothing above or beside me. Sheer openness. People ask me: Why climb if you can’t see what’s there? I can’t see the view, but I can feel it. I use my other senses to take in a mountaintop. I think of the smells, the wind, the sun on my face. That summit is the most beautiful thing I’ve ever felt—and my sighted partners agree.

—Trevor Thomas, as told to Casey Lyons

PERFECT 10 MILES Perfect 10 John Muir Trail from Crabtree Ranger Station to Mt. Whitney

MAP Mt. Whitney Zone ($10, tomharrisonmaps.com)

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