At a concrete water cistern next to Barrel Springs this morning, I found a young man named Joshua stretched out on a ground cloth. He’d had a terrible day and night, having left the last water hole 24 miles back with just four liters of water in his pack, counting, a little inexplicably, on finding water at a cache called Third Gate. It’s late in the Pacific Crest Trail hiking season here, and the cache was empty. Joshua ended up walking through the night to stretch his water. He still ran dry a few miles short of Barrel Springs, and by the time I found him he was thoroughly rattled.

“I feel like I left a piece of my life back there on the trail,” he said. “And tell your son he needs to carry eight liters of water on that stretch.”

It was a beautiful morning, and I was enjoying the well graded trail south of Barrel Springs, zoning out and walking fast and mulling Joshua’s story — I seemed to remember Noah was carrying only four liters’ worth of canteens — when I looked down and realized I was stepping over a rattlesnake in the trail.

Right over him. One foot was to his north and the other, to his south. I kept walking two more paces and turned around. Then, and only then, did he rattle, that distinctive sound made rather less obvious by the morning wind in the chaparral.

He had been lying directly across the trail, sunning himself after the night’s chill, his head buried in grass to my right and his tail in the grass to my left. The breeze in the grass probably kept him from hearing or smelling me; for my part, he probably registered to my eye as a stick. Fortunately I usually don’t step on sticks, having lost my footing on a few. I took some photos and was on my way, grateful that rattlers aren’t aggressive at all.

But for the next hour I jumped out of my skin with every passing ground squirrel or lizard or gust of wind in the bushes. And when a horned lizard shot across the trail and collided head on with my right foot, my adrenaline level reached for the stars.

I walked out about seven miles, had lunch in the blasting sunlight — not a whiff of shade on this trail — and headed back to the car.

Noah, meanwhile, was having a tough day of it to the south, where the trail is not so well graded or pleasant to walk on. We needed to get him more water bottles, so when I discovered he was headed for a trailhead just a half hour from my motel, I drove out there in the evening and picked him up for a shower, dinner and the other bed in my room. Oh, yes, and four one-quart Gatorade bottles.

I found him at another depleted water cache, which looked like the remains of a refugee camp.

On the way back to the car, we saw another dad’s message to a hiking son, drawn in the sand.

This morning I popped a CD of the Puccini opera “Lucia di Lammermoor” into the car stereo as I drove up to the trailhead. The incredible music was the perfect way to smooth out some of this week’s bumpy emotions.

What a perfect match, opera and desert: Grandeur meets grandeur.