Yosemite National Park, Calif. ? Clutching a steel post in my right hand, dangling about 300 feet above the weathered granite of a canyon ledge, I struggled to get a hold on the cliff. The National Park Service notice at the trailhead had said, “Half Dome cables to be taken down for repair this Sunday.”

Now I realized why.

I had hit the trailhead at dawn for the bald gray peak of Half Dome, 4,737 feet above the valley floor at Yosemite National Park in California. The trail was long, 16.4 miles. And it was steep — nearly vertical on the final approach.

My trail book had described it as a two-day hike. But I did not have two days, and I was 17, strong and fit. I decided to get an early start and just push it.

The morning air was cool as I moved up a trail shaded by towering pines. It led to Vernal Falls, one of Yosemite’s landmarks and as far as most walkers get on the trail, although it would be only the first stop on my hike.

Less than a mile along, I could see the waterfall at the end of a canyon. Along the canyon and down both sides of the trail, shrubs and flowers were misted by its spray, a permanent morning dew. I climbed a staircase hewn out of the canyon wall, 300 uneven steps. This was the Mist Trail, named for the spray thrown upon it by the falls.

From the top of the falls, the Merced River plunged between the green canyon walls, running under permanent rainbows. I could feel the life of the canyon and the river as it rushed over the cliff. I felt fresh and ready for the day. I paused a moment to enjoy the feeling. Then I pressed on.

An early start

The trail took me up through a peaceful wooded set of switchbacks. But I could hear a growing roar as I approached Nevada Falls, where the river plunges onto boulders 600 feet below. I had made the approximately four miles from the trailhead to Nevada Falls in just less than an hour.

Up to this point, the awe-inspiring scenery had improved with every foot of elevation I gained. But the path above Nevada Falls was disappointing. There were several miles of nature trail — brown dusty dirt and brown dry bark, essentially just a way through the woods. Although it was pleasant enough, it was a letdown from the spectacular views I had seen only minutes earlier.

But this was my first real test of will. The trail, at first a gentle incline, quickly increased to grueling steepness. My legs burned as I took each step. My skin was gritty from the dirt and hot from the sun as the morning wore toward noon.

Trail dust parched my throat no matter how much water I drank. But I continued, past other hikers and past the campsite meant to split the trek into two days, and onto the next-to-last leg of the journey. This is where the trail began to grow steeper in earnest.

There was a small metal box where campers could store food and other items with scents that could attract bears. Directly in front of the box, I could see a series of switchbacks as steep as most staircases. I started to climb the switchbacks.

Despite the extra effort, or perhaps because of it, I was beginning to get into better spirits. The feeling was short-lived. A mile or so farther up the trail, I reached the treeline, the point at which everything stopped growing.

Looking for shadows

The round bulk of Half Dome, like a section of a baker’s loaf stood on end, could be seen for what it was at its core — weathered granite. It had taken me three hours to go the first seven miles up the trail. It would take another hour and a half to make it the next mile.

Half Dome is incredibly steep. Chunks have been cut out of the rock to help hikers, but they were unbelievably easy to miss. In the midday sun, the steps’ shadows were almost nonexistent, and it was nearly impossible to determine where they should be except by looking for their shadows.

I must have spent 15 minutes looking for steps. To be honest, a few times I just clambered over the unhewn rock. At this point, nothing could stop me. The peak was just over the next ridge, and being so close to it, four hours ahead of schedule, made me feel lighter than the mountain air.

Then I reached the final approach, and I realized why the trail was considered so difficult. Ahead of me was the rock, growing exponentially steeper to the point at which it looked nearly vertical. To aid in the climb, steel cables had been strung between steel supports that were sunk two feet into the granite.

There was a large pile of leather gloves at the base of the climb, placed there in anticipation of the damage that steel cables can do to bare hands. The gloves were old and worn from countless hands making countless trips, and as I did not have my own, I was extremely grateful for them.

A close call

The ascent started at an easy grade but quickly progressed to one that I could not climb simply by holding onto the cables alone. I started to haul myself up by also grabbing the posts themselves, and I quickly settled into a rhythm — left hand grab cable, right hand grab cable, pull; left hand grab cable above post, right hand grab post, pull.

A post came out in my hand and my feet slipped out from in front of me. My cheek slammed against the cliff face and I white-knuckled the cable as the post waved uselessly in my right hand.

I glanced at the ground. That was a mistake. Gray granite lay some 300 feet below me. From my position, it seemed miles away. In truth, it might as well have been.

I searched the rock with the pole, feeling it scrape until it dropped into the posthole just as I heard the curse word I had screamed as the support came loose echo back to me off the mountains.

I needed a minute to recover. But I didn’t have a minute. I was walking up the side of a mountain. I was holding myself up with my arms, and they were long past aching. So I pressed on, nerves as shaky as my grip, my body swaying on the cables with every breeze.

Finally, the path up began to level out. As I came over the top, and out from between the cables, I saw a treeless plateau the size of 17 football fields.

It had taken fully an hour to make it up the final 400 feet. But the view was well worth it. All around me were great gray mountains. The grassy and wooded valley floor stretched out below me like an ocean. At the edge of the summit, I looked straight down on the pines. They looked smaller than those in model train sets.

Triumph at the top

It was an entirely different feeling at the top of Half Dome. All of us who reached the top that day were members of an exclusive club. We had all passed a test of will and shared a feeling of triumph. I spent two and a half hours at the top, talking, taking pictures and enjoying lunch.

I spent as much time as I could before I walked back to the steel cable trail for the trip down. Just as the climb up was the most physically difficult part, the climb down was the most mentally difficult. Staring at the rock from the peak of the trail produced a sensation similar to the one I get before rappelling. But this time, no rope tied me to anything.

Returning on a path rarely feels like it does heading out, and this hike was no exception. The long dusty nature trail, which took an eternity going up, passed by me in a heartbeat going down. My mood had changed from determined exertion to placid acceptance. I still had to put out effort to keep heading down the mountain, and I still hurt. I just didn’t care.

As I walked again under the pines that lined the trail to the parking lot, my body was stiff and tense but somehow rubbery. I was tired from the effort but proud of my success.

As I left the trail, I was glowing.