I could imagine the Beaver Dam Mountains in the summer: blast-furnace heat, a scattering of buzzing insects, brassy sun, the dry vegetation, must turn it into something like hell. But when I was there two weeks ago it was a mild spring day.

It was three days before my 45th birthday, and sometimes those major milestones start looking like tombstones. I was thinking about my mortality.This was a Joshua tree wilderness in extreme southwestern Utah, a couple of miles inside the border. I drove alone on U-56 along the Castle Cliff Wash and stopped to explore at a dirt road turnoff about 131/2 road miles north of the I-15 turnoff near Littlefield, Ariz. The dirt road wandered off the road toward a steep flank of the mountains, and I went through the wire gate, parked by a giant Joshua and hiked.

It was a landscape like no other in the state, because of the Joshuas with their uplifted arms and the other Sonoran flora. Rolling hills quickly led to the mountains. Plants were stratified in life zones, with Joshuas, yuccas, cacti and sagebrush lower, giving way to pinyon-juniper uplands as I walked higher.

The Joshuas had already flowered, leaving papery white remains of flowers dangling from skeletal cone structures at the ends of branches. The yucca seemed to pluck at my pants legs, and I had to keep reminding myself not to anthropomorphize.

Disgustingly, some louts had left trash close to the dirt road: Articles of greasy clothing, boards that washed into a gully, a big rusted cowboy stove, scraps of foam rubber from a sleeping mat, carpeting; broken beer bottles glittered here and there; flattened beer cans were faded to an overall silvery tone.

Some of the cacti were unusual: a fat barrel about six inches tall wasn't quite like any I was familiar with. And several species grew on low outcrops of crumbly rock.

One species of cactus was blackened, uniformly, wherever it occurred. It looked like the claret cup cactus, growing in clusters along rocky flat places. Every group of this type looked like it had been burned in a fire, in some plant cataclysm. But different varieties nearby positively thrived.

I puzzled over that, trying to figure why one species was blasted and the others were doing fine. Maybe last summer was terribly hot and dry, I decided, and the least-hardy species was killed; perhaps that is how a plant's range changes as the climate fluctuates.

If they were claret cups, it is unlikely they were done in by cold weather during the winter while others survived, because claret cups grow far to the north. They are common in the San Rafael Swell, where temperatures plunge to around zero sometimes.

The fat, swollen prickly pears were topped with tight buds close to blossoming. Soon their silken yellows and purples ought to be attracting bees.

Cholla were literally clad for spring's arrival, wearing bright green velvet and new-looking spines. I was struck by the strength of a huge dark juniper, which I imagined standing in the same place for 80 or 100 years, lifting its bush upward like a flame.

The clear air had no scent, but smelled fresh the way that clean water has no taste. A huge bird with flat wings soared easily from above the mountain and lost itself in the sun's glare, maybe an eagle. I was floating too, in a way - hiking effortlessly, scaling slopes and mounds. Maybe the lower altitude gave me greater stamina.

Nearly up to the cliff face, I sat under a big pinyon. Ants swarmed over a dead branch. The breeze made a sound like a hurricane, blowing through the needles. The pine and a smaller juniper had reached some kind of accommodation, nearly enfolding each other, but with their limbs not quite touching. It must be that when the wind rubs a pine limb against a cedar limb, this causes their growth to somehow vary so that the limbs don't mash together.

As it was, the two old trees looked like lovers or boxers, locked in a decadeslong embrace.

A bird chattered "hiya, hiya," and then came a flock of little callers chirping. "Beee," said something else.

Marine fossils - corals and the tracks of long-extinct worms - formed a bas-relief eroding from the hard dark rock. Sitting in the pinyon's shade, I stared at the rippled surface of one block that caught the sunlight and thought it was strange to relax on this desert mountain while seeing undersea tracks.

I felt a deep sense of happiness at nature's continuation.

How good it is that the wind has been blowing through the pinyons for thousands of years, and yuccas have been stretching out their rigid fronds, and the sun has been sending its strong strengthening rays to all this life for so long. How satisfying it is that all this abundant life will continue after I am dead.

Thank heaven for spring.

During the grand cycle of renewal, we are reminded that man is only one part of creation. To grow, adapt or not, reproduce, die - the natural movements - these follow immutable laws that apply to ourselves as much as to the claret cup cactus. And for just a moment, through a powerful sense of acceptance, I found peace. It came to me that none of those movements are terrible, not even the end of life.

Let it be, let it be.