In the third week of August someone pushes the button and brings summer to an end in the Mountain West, though beautiful weather and Indian summer lie ahead. Typically the change comes with the discharge of a powerful thunder cell, seemingly no different from any other electrical storm but collapsing into a gray leaden overcast instead of propelling itself onward through crystalline skies. The rains continue for a day or two, then cease. The skies clear, and nothing appears changed. But everything has changed.

Early in August, the birds begin to leave: some of the songbirds first, then the Canadian geese in military formation, and eventually the sandhill cranes, high-flying and confused as smoke, gathering only to twist apart again, cranking their rachitic cries distantly out of a cyanic sky. Pale underbodies nearly invisible against the sun’s glare, they beat raggedly away toward the bosques of the Rio Grande south of Albuquerque, toward Mexico. By Labor Day Mexican, Basque, and Indian herders are driving the sheep down from the alpine meadows into the hills above the creeks and rivers, for sorting and then for trucking to their winter range. Early last September I went with the Thoman family to Kendall Bridge on the upper Green River 15 miles below the Green River Lakes. We slept over the night at camp and in the morning rode horseback up to a grassy park where Bill Thoman, his son Dick, and Dick’s wife Susie, with the help of a pair of Indians, had arranged the steel panels trucked in by pickup to form a series of pens and a funnel of wire fence drawing to them. The herders drove the sheep at the funnel where they milled and climbed on one another, bleating, while Dick and Susie and their seven-year-old son Ben walked through them from the funnel’s neck to its mouth, flailing at the animals with their coats to drive the flock more closely together still into the funnel as the Indians stood watching the dogs work and I sat my horse and now and then pushed back a straggler.

As the sheep passed singly along the narrow corridor formed by the panels, Bill worked the gate to deflect them into one or another of the pens: wethers, ewes, the large strong bucks, and the runty ones to be castrated. We seized the animals behind the front legs, threw them, sat them on their rumps like teddy bears, and held them while Dick twisted the tails off, and, operating with a penknife, slit the scrota and tore out the testes with his fingers; after he stepped aside, Mickey Thoman injected the sheep in the inner thigh with penicillin and daubed a disinfectant on the wounds, and Mary retrieved the sundered parts in a pan for lamb fries. When Dick had finished notching ears the herders pushed the bloodied sheep into the hills again, and we drove the bucks down to Kendall Bridge where the truck waited, a semi coupled to an aluminum stock trailer. The aspen jetted from the ground like yellow gas flames streaked with green, the parks bristled with the golden frost-killed grass, and beyond the meandering Green the northern abutment of the Wind River Range stood hugely in cross section, blocks of pink granite thrusting above a pedestal of black timber, tilting against a suddenly overcast sky, waiting for snow. That night a cold torrential rain fell driven by a shrieking wind; at dawn the tents were frozen stiff and a thick fog packed the valley. Driving home, I saw that the highest peaks—Gannett, Coolidge, Fremont—had received a dusting of snow, and by the time I arrived in Kemmerer late that afternoon the great and silent stillness of fall had embraced the town. Tom Eliot to the contrary, April is not the crudest month.

The first snow, usually in the initial week of September, draws into the parched ground within hours, and for weeks afterward the sky remains remote and intensely blue. Out on the desert hunters pursue the wily antelope whose dark and globular eyes can read the number on your hunting permit from a distance of half a mile and whose sole means of defense is flight, at speeds to 40 miles an hour. Their tan and white coats make them fairly easy to spot at a distance; after selecting for height of horn above the ear, curve, and thickness, the hunter begins a stalk on his quarry that can last hours, or all day. He creeps up dry washes on hands and knees, crouches movelessly in excruciating positions behind small clumps of sagebrush, and crawls on his belly to the shaly verges of canyons over a carpet of prickly pear that deposits its fiery spines in the palms of his hands, in his chest, stomach, and legs before he has a chance to pull the trigger. Once while chasing a splendid buck I almost stepped on a large badger playing possum in the brush. Since I was too far from the prey for a shot and didn’t want to spook him by appearing over the rise between us, I sat for a time with my rifle across my knees watching the badger, who presently opened one eye and then shut it quickly to convince me of the actuality of his demise. A wilderness of deep basins walled by steep cliffs striped red and white, mesas buttressed by masses of gray, green, and cream-colored clay like the fossilized feet of giant pachyderms, smooth golden hills separated by folds of lavender shadow, and juniper breaks growing upon islands of red sandstone rock—the desert stretches in every direction to the horizon and the far blue mountain ranges that triangulate it. The lone hunter, hearing the wind pass slant across his ears, observing the dust devils run twisting over the sagebrush plain, and feeling in his bones the acute emptiness of fall, knows that he is precisely that: alone.

Before the Wyoming Game and Fish Department split the deer and elk seasons from each other ten years ago, moving up the deer hunt to the first two weeks of October, I made a fishing trip to western Montana every fall before returning home for elk camp. By early October the tourists are gone from the Yellowstone and have been replaced by flocks of waterfowl without number, blackening the glassy surface of Yellowstone Lake. Trout feed ravenously before winter, and the fishing is superb. A dozen years ago my wife and I, hurrying to make Rock Creek near Philipsburg, Montana, for the night, called it quits at Hebgen Lake on the Madison River around nine o’clock and followed a jeep track away from the highway into a timbered gulch. We pitched the tent in the darkness at the edge of a small clearing, crawled in, and fell immediately asleep. At a little past two in the morning I was wakened by the sound of padding feet around the tent; clockwise, counter-, then clockwise again. I reached for the .41 Magnum hoglegby my side and quietly woke Norma. “What is it?” “We have a bear in camp.” “Are you sure it wasn’t me snoring?” “That’s what I thought. It’s not you. Listen.” We listened together, Norma still on her back in her bag, I sitting upright as the bear continued to investigate us. After a time we heard him no more, and I fell asleep with the gun on my chest. In the light of morning, we discovered that we had raised the tent beside a well-used game trail going down to the creek a quarter of a mile away.

On Rock Creek, casting a Number 6 Bitch Creek Nymph from a Number Eight fly rod, I caught five fat and shining trout from 18 to 22 inches long between six and six-thirty on a single evening while watching a black sow bear eat berries as her two cubs played along a log on the opposite bank of the stream. I released all but the best two, disassembled the rod, and drove back to camp on the trail above the water’s edge in the gathering darkness from which a brightness appeared, like that of a distant city in flames. Reaching camp a half-mile farther on, I found it spectacularly illuminated by a tremendous bonfire of resinous stumps and logs that Norma had built for a bear fire, not trusting to the .41 I had left with her. Late in the afternoon she had witnessed two more bears scrambling along the talus slope on our side of the river, and decided on the fire as the more reliable form of protection.

But western Montana, despite its great and still largely unspoiled beauty, is a disquieting place. Thomas McGuane, the novelist, has his talent, his money, his cutting horses, and his lovely wife: why does he need also his cretinous and sybaritic Hollywood friends, to whom he has sold property in the neighborhood of his ranch in McCloud ? Today, you can saunter down the main street of Big Timber and see Whoopee Goldberg jump on her horse and gallop off to arrest a gang of white supremacists holed up in the mountains nearby. Not far away, Ted Turner and Jane Fonda have bought a ranch, torn down the previous owner’s barbed-wire fence (made by the bloody sweat of his brow), and overrun first-rate cattle range with a herd of woolly, pig-eyed, moth-eaten, and brucellosis-infected bison. And the once simple and pleasant town of Missoula is a polyglot mess now, filled with hippies, yuppies, environmentalist groupies, second-home owners, professors, and students; the lovely Bitterroot Valley subdivided almost as far as the pass.

We of Kemmerer, Wyoming, should feel slighted: the Californians love us not for ourselves, nor for our sagebrush-and-bentonite scenery, but for the usually thriving deer population in the surrounding desert hills. By late September they have begun to arrive in Winnebagos towing jeeps and ATV’s chained to flatbed trailers. Those that do not camp in the hills do so in town, bleeding out their kill in the bathtubs in their motel rooms. Last fall we saw very few of them, word of the crash of the southwestern Wyoming deer population apparently having reached Greater Los Angeles. Those that did come got here in time to experience the conclusion of the drought, which broke at last on the first day of October with torrential rains, six inches of snow in the high country, and a foot of mud in the roadbeds.

Four seasons ago, encouraged by the fine Indian Summer afternoon and optimistic weather forecasts, I overrode my better judgment and parked the truck and horse trailer at Fontenelle Crossing rather than drive the six miles on to the gravel road at La Barge Creek. The rain directly followed the morning hunt the next day and continued until dark. The morning after broke clear and warm with a springtime softness in the air, the kind of weather that makes experienced hunters nervous. My partner was expected at work at two o’clock in Kemmerer. We struck camp, loaded the horses, and had ridden out a quarter of an hour when the snow began to fall. At the crossing it was raining, the road a morass. We unloaded the gear into the truck bed, uncoupled the trailer, forded the creek on horseback, and rode on to Kovaches’ camp, where they agreed to keep the horses through the week if necessary; one of the sons took us by jeep back to the truck. When I had driven a few hundred yards, it became obvious that four-wheel drive alone was not going to get the job done; we climbed down into the cold mud and lay on our backs in it, adjusting and hooking the tire chains around all four tires. Then we drove on at ten and fifteen miles an hour toward town, forty-five miles away. Some years before another hunting party, driven out of the mountains by storm, found the same road covered by two and a half feet of snow. They took turns digging ahead of themselves with shovels, then butting the cut with the lead truck to further their progress. In this way, the convoy made the ploughed road at Krall’s ranch, seven miles distant, in two days.

In summer the mountains are a second, infinitely expansive, home; from early fall until the following summer they are a likely ambush, a potential trap. Always by elk season the hunter is himself the prey. That high overcast, that slight shift in the direction of the wind: these are among the signs that danger threatens. Looking up the black spires of the trees to the cliff face that appears to be falling constantly backward beneath the forward-moving sky, one feels in the pale light, the cold shadow, a sense of the country against him, and something like fear.

The day after the first winter storm has dropped several feet of snow in the mountains, the elk migrate by the hundreds from the high country toward their seasonal range, bounding down from the timbered slopes through chest-deep powder, across Fontenelle Creek, and over the sagebrush flats. In the collective rush they are oblivious to the hunters who have their choice of three, five, seven trophy bulls tP shoot out of the herds in a scene that is reminiscent of the 19th-century slaughters and ends with a dozen gut piles steaming in the trampled and bloody snow. It is an easy way to hunt elk, if your timing is right and your luck good. Also your battery. What that late October storm means is that someone has punched the second button, and the Great Portcullis has begun its descent. You do not want to be caught on the wrong side of it.