The largest grouse--the sage hen--must have sage, and sage depends upon the price of wheat, the need for coal, and the living space that man demands.

Before the buffalo and the cattle grubbed down the tides of grass, the sage existed mainly on only the higher ground. But the shrub spread its range where the grass gave way and some of the grass eaters changed their life styles. The pronghorn was one. But the sage hen seems always to have favored the sage brush.

Because of its sameness the sage seems endless, and where it still stands man has left little mark. The double trails of rattling pickup trucks are not much different from those of creaking wagons with grunting oxen and the landscape of brush and towering sky seems even more lonely when it is broken by the tiny cipher of a monument. "Sheepherders' monuments," we say, although any lonely man on any timeless mission could have built one--a little tower of stones that was likely to be the most permanent mark he would leave upon the world--to last longer and to be seen more often than his gravestone, if he was to have one.

I think of sage hens and "monuments" together as I think of sage hens and prairie-dog towns, distant antelope and drifting coyotes, turning golden eagles and the sandhill cranes going south. And although it can be that way, I find it hard to remember sage hens flailing at sage and rabbit brush at my feet in a touch-and-go duel with gravity--the procedure that causes better gunners to say this is no game bird.

I think of sage hens as moving shadows a quarter mile ahead on stony ground that has kept the sage thin. I know they are watching me and probably will not wait, and I can remember them flying higher and higher to set their wings briefly and choose a course, whereupon I always say exactly the same thing:

"They're leaving the country."

And there is the little bunch at great height, flying against a chilling backdrop of snow-promising sky and over a white spine of the Rockies toward some winter range I do not know.

WHEN THE HISTORY BOOKS FIRST SPOKE of the "prairie chicken" they undoubtedly meant sage hens part of the time, but after Lewis and Clark met the grizzled, hump-backed bear they were not likely to go deeply into the taxonomy of plains birdlife. And the mountain men and then the settlers who came afterward saw the plains' birds as essential though sometimes infrequent meals. Some were simply larger than others.

Then there were graceful rifles that came from Pennsylvania by way of Kentucky, and there were a few sleek fowling pieces; but it is likely that more of the sage grouse fell to nondescript guns remade from muskets of the Revolution, and few birds were shot in flight. When man is a stranger, sage hens are fools.

Only a few years ago the sage hens became so scarce that it seemed hunting them was gone forever, but then they came back to open seasons over much of the West. The farthest north I have killed a sage hen was in southern Alberta.

The danger now is the immense articulated diesel tractor that can rip up sage-covered land the pioneer's sod plow could not turn. That will depend upon how beef and wheat profits compare and how the cattleman judges the use of chemicals for pastureland. Sage grouse are primarily leaf eaters, although their rather flimsy gizzards may contain some grain. And while they may search for green shoots in stubble fields and love alfalfa, the sage is never far away.

Few know sage grouse except from the pictures taken or painted during the grouse's big scene in early spring as the snows are going and the cocks gather at their strutting grounds in displays only the wild turkey can rival, but only because he is larger. Indian costumes for ceremonial dances were made more in imitation of the sage grouse than of the eagle. Except for the mating ritual the bird merges with the sage and excites no magazine covers.

Crawling sweatily through a dry wash toward a herd of antelope I had stalked for almost two hours, I saw my first sage grouse, apparently either a seven-pound quail or the product of a rebelling nervous system. I was crawling on a plane with jackrabbit droppings and an occasional dried bone of indeterminate origin, and he seemed to tower above me as he stood with upstretched neck. When I described him as a seven-pound quail an editor deleted it with no stated reason. I submit the comparison again as a sort of test.

Like gunners who assign a certain speed to each game bird and do not concede he can go faster or slower, casual observers of sage grouse make factual pronouncements that startle more careful students.

A sage hen will sometimes stand and watch a hunter's approach with no effort at concealment, leading to the instant conclusion that he can neither hide nor run, but he does both very well.

Bobwhite quail that move 200 yards under the frustrated supervision of pointers are called "running birds." A bunch of sage grouse will go just faster than a man's walk for two miles--and when a hunter or his dog finally gets too close it may be that only one or two birds go up, the rest having disappeared in cover somewhere along the route. But you may hunt sage hens for years without such an exhibition.

There are times when birds of the year will make a foolish attempt at concealment in close-cropped grass several feet from the sage, but the adults hide well when they try, and a hunter sometimes brushes a five-pound bird with his foot before it batters its way into the air, a disconcerting experience that sometimes results in ridiculous shooting displays. Remember that in early season there may be alert rattlesnakes in sage grouse range.

The giants are the cocks, perhaps even seven pounds, while the hens are more likely to weigh a little more than two. When they walk, the cocks have a tendency to waddle; the hens walk evenly, their feet apparently put down with deliberate caution. But in the air the hens execute a violent twist at intervals as if one wing might have failed momentarily--and when it occurs as a shot is missed the gunner is likely to feel he has a hard cripple. This twist-in-flight appears not only in escape. I have watched it in birds flying so high that I might not have identified them otherwise.

TO MOST GUNNERS THE SAGE GROUSE is an incidental bird to be pursued only the first day or two of the season, and the methods used are hardly aesthetic. A row of shooters in skirmish order will kill sage grouse, especially early in the fall, and the score is aided if they have a flushing dog or two. Birds of the spring hatch make mistakes in the direction of flight they choose.

Where early-season birds are fairly plentiful and the sage spotty, binoculars work for hunters who simply park a truck and scan surrounding hills. If the birds move about, they can be seen, slow-moving dark spots against sun-cooked grass; but if they are resting, a long inspection reveals nothing but possibly a drifting coyote or antelope or a searching hawk.

There are formulae, however, for resting sage grouse. In typical sage habitat they are most likely to be in the draws--where the sage is heaviest and not far from water; and if the water's edge is muddy, their big tracks are a sure thing in an uncertain business. Then, of course, there are the droppings to look for, subjects of endless argument, for no one knows just how long sage-hen droppings will survive the seasons. A year? Two?

The shredding gray ones, widely scattered, mean simply that a sage hen (possibly long dead) has walked that way. If there is some green and black in the droppings, they are fairly recent. If they are clustered in piles, the birds have rested there, each leaving his own collection. And "caecal droppings," black liquid that hardens in temporary blots on the ground, mean fairly recent bird presence.

Last fall we went to new sage country and we were late. The first shooters had driven the Bureau of Land Management roads in eastern Montana, and here and there the sun glanced off empty shotgun shells in or near the trail. Several times we found scattered feathers where someone had dressed his kill. It was warm and dry despite our lateness, and more than a mile away a film of dust rose over someone's cattle herd being relocated for the late fall. Dust swirled inside our truck, too. But dry weather can be a help, for although it may be that sage hens can live on dew, they will try to stay near water.

We came to a classic spot, a valley with heavier sage along the nearly dry creek, bare shoulders on some of the slopes and little grooves with thicker sage and rabbit brush near the ridge crests. On the ground was scattered winterfat, the earth-hugging little plant sage grouse are supposed to favor when the northers drive buckshot snow across the flats. There were no really high hills, just several knobs with their miniature walls of rimrock, and some irregular white dots near the horizon instantly translated into a band of antelope who had watched us since we first entered the basin. And to make us feel at home, there was a solitary herder's monument, like an overweight fencepost on top of the highest hill.

I put down the dog, an orange-and-white Brittany with more steam than judgment, and I watched him tear up along the nearly dry creek. An orange-and-white dog is discord in purple sage, an interloper where canines should be grey and ghostly.

I found fresh sign within a hundred yards and watched my emissary hopefully as he left the bottom and swept the slopes, one slithering stop and stylish point crumbling to embarrassment as a lazy jackrabbit loafed off ahead of him, loping sidewise. On some days the dog might have chased with urgent yips, but this time he pretended not to notice.

The basin bent to the right and the dog came back to heavier brush near the bottom and was out of sight. Then part way up the slope he reappeared to point so far ahead of me that I despaired of getting there in time. Fidgety dogs do not display their staunchest qualities when large birds stroll about them like field-trial judges assessing form.

Several birds went up in a scatter--bulky forms skimming the sage at first and then towering slightly to spread out and soar over the hilltop. The dog, evidently feeling his primary mission had been accomplished and that it was now time for a bit of relaxation, then methodically put up a dozen more, one at a time, while I screamed helplessly.

But by then I was within a hundred yards of him and he eyed me with some apprehension, loped off to one side and pointed rigidly. When I was still 20 yards behind him a sage hen went up 10 yards ahead of him and I killed that bird. Then the same thing happened again, after which came a humiliating miss with both barrels.

We turned back toward the truck, for some of the birds had gone that way, and I cut across a hill to shorten the trip and, as usual, was amazed to see that the truck was only a blue speck. Until then my legs had not seemed tired. Now I was thirsty and even contemplated the grimy canteen I had brought for the dog.

Back at the truck the panting Brittany circled a little and pointed scarcely 50 yards behind it. Then we were really in sage grouse and they went up all around me, all seeming to eye me as they chose escape routes. I killed the third and final bird of my limit and wondered how so many had moved into the area. I investigated the sign and recalled the direction my dog had gone when he first struck the ground. He had simply missed them, and a dozen limits of sage grouse had been there all the time while I had tramped miles of sage.

THERE ARE, OF COURSE, PERFECT PLACES for sage grouse that never seem to hold them, and other areas that seem no different from a hundred surrounding square miles but that have had sage grouse for the 20 years I have hunted them. There is one such place, a little island of sage brush half a mile distant from thousands of acres of solid growth. The little island of brush sits in grassland, and there a little bunch of sage hens has been for 20 years, possibly a hundred years for all I know. Perhaps some of them were part of the winter meat for the homesteader whose cabin slowly crumbles in dry wind beneath the ridge a mile away.

It is the fall and winter concentrations that most confuse sage-hen hunters, and an area that has been hard hunted with scanty result at the season's beginning may suddenly be alive with birds at some later date. It happened to me in good antelope country when I came back to a sage-grouse hunting spot as the pronghorn season opened. There was spitting snow where the sun had broiled me and a pair of huffing dogs a month before. And there were several hundred acres of sage grouse, seemingly spaced for the hunter's convenience and going up with predictable regularity. I assume they had moved in for the winter but the location of such a rendezvous is not always the same.

And such a concentration is not necessarily a hunter's heaven. Last year, confidently hunting country where I had killed early-season grouse without much difficulty, I found the area seemed suddenly deserted. There was probably six square miles of it with all the sage-hen necessities, including two herder's monuments and the remains of a weathered homestead.

We had hunted all day without sight of a sage grouse and the ones we finally saw went up wild. Wild for the dog who could not hold them and very wild for us, the flushing birds gathering others as they went until there were a hundred against the evening sky and they became specks and disappeared with no sign of alighting. And this time there were no sleepers, no sluggards to wait us out and croak up under our guns. All of them were together and all of them had gone.

When roosting, sage grouse tend to stay fairly close together, but the average flock put up in daytime will be spread out, perhaps over 50 acres or more and scattered so thinly that I cannot say how they get together again. The "sleeper" is the bird most frequently bagged and he is nearly always there if the flock is big. Perhaps he may move hardly at all in the 12 hours after the main flock leaves, and many times I have returned after a long hunt to try once more where I had previously given up, and found one or two birds still there. Of course, occasionally they have returned after flushing earlier in the day, this being a rendezvous point.

BUT IT IS HIS HOME THAT LURES ME after the sage grouse--a country scorned by sightseers and called simply "empty" by passersby with their eyes on distant peaks or singing forests of pine.

There was the trip with Charles Eustace in eastern Montana. A game biologist, his job was to catalog the sage-grouse population, and he took us hunting; but he mentioned a spot where he wanted to eat lunch and was almost insistent although it seemed to be out of our way. He was a new acquaintance and I humored his whim.

It was a rather steep grade that the old Blazer clawed at briefly and then we were at the base of a butte, a flat-topped promontory thrust up at the edge of an immense sage flat that seemed to extend forever through thickening haze toward North Dakota. Around the stony base were Indian designs, many of them the reproductions of animal tracks, and there was the childish hacking of a few modern vandals.

Then we climbed to the top, a winding way of only a few yards and of no great difficulty although there were no steps.

And on the top, carefully designed to cover attack from any direction, were rifle pits--appearing haphazard at first, but laid out with geometric precision so that no attacker could approach the natural fortress unseen.

"No, I don't think Indians ever dug rifle pits in this country," Eustace said.

So who, I wanted to know, gouged out the deadly little trenches? It had been long, hard work. I waited for the answer. Ranchers fighting cattle thieves? Cavalry standing off Indians? Outlaws making a last stand against an awaited posse? Range war?

"I don't know who dug them and I can't seem to find out," Eustace said.

And I don't really want to know who did it. I have seen documented and landmarked battlefields.

Eustace looked off toward the Dakotas and endless sage.

"Certainly is good sage-hen country," he observed.