IT'S 20 minutes past sunset out on the Oklahoma prairie, and the herd is grazing peacefully in a pasture. The cowboys, weary from the day's ride, lie in their bedrolls by the fire. As if on cue, the lonesome wail of a harmonica fills the night.
But this is not a Bulls-Eye barbecue sauce commercial.
These genuine cowpokes, all 30 of them, are part of a six-month odyssey known as ''The Great American Cattle Drive of '95.''
Ever since it clip-clopped out of Fort Worth, Texas, on March 5, this elaborate historical reenactment has been creeping slowly north with 82 horses, two covered wagons, and 300 longhorn cattle in tow. Their destination: Miles City, Mont., 1,600 miles up the trail.
The drive is the singular vision of Bud McCasland, a former telephone- company executive from Fort Worth who has what friends describe as a bad case of ''cowboy on the brain.''
After five years of planning and an undisclosed sum of his own money, Mr. McCasland has brought his ultimate fantasy to life. When it's all over, he and his boys will have passed through six states and more than 100 towns, earning a place in history as the first great cattle drive since 1886 -- and perhaps, the last.
Just like their 19th-century predecessors, McCasland's wranglers jog the herd 12 to 15 miles a day, sleep out under the stars or in tepees, and sing cowboy songs to calm the herd.
Out of the back of a chuck wagon, Dennis Dobson (''Doc'' for short), cooks two meals a day with cast-iron pots and skillets. Tonight's dinner, says trail boss Jim McElroy, was a dish called ''sonofagun stew.''
''Best you ever had,'' he says.
But as authentic as this cattle drive appears, a cowpuncher today has obstacles unheard of in the 1800s.
Drover Mike Austin notes that they're confined to the only open spaces left in the American West: roadside ditches. They also need a police escort to contend with things like road crews, bus loads of German tourists, and stop signs.
''I still can't figure out if 300 cows have the right of way or not,'' Mr. Austin says. ''I guess that's what the cops are for.''
But the cowboys' biggest concern is that an unusual sight or sound will spook the cattle and cause a stampede. This usually involves running straight ahead for as many as two miles, blind to everything in the path.
Early in the trip, as Austin tells it, the herd stampeded alongside a Texas highway. Six cows broke off and galloped straight down the middle of the road. Traffic stopped but the cows did not. Before the cowboys could catch up, the loose cattle ran up the hood of a Lincoln Continental, across the roof, and down the trunk.
When the cowboys finally headed them off, Austin says, the cows turned around and ran back up and over the Continental. ''We had a pretty scared lady in that car,'' Austin recalls. ''Can you imagine trying to explain that to your husband?''
Trail boss McElroy, who runs the day-to-day operations of the drive, is somewhat less tickled by the mishap. Tall, thin, and bowl-legged with a white moustache and a cold eye for mischief, this former Oklahoma state trooper makes it clear that he and the boys know what they're doing.
They received more than 2,000 applications from would-be wranglers, he says, and only the most experienced riders and ropers made the cut. While many of them left jobs as computer technicians, truckers, and construction workers, McElroy says, ''there ain't a greenhorn in the bunch.''
Besides, after 425 miles, the chances of another stampede are slim. ''I reckon these critters are so trail-broke,'' McElroy says, ''that you could take them to town and march them in somebody's front door and out the back.''
While no one has invited the cattle to tour their living room, the drive does generate excitement when it passes down main street in small towns like Buffalo, Okla. It also generates a few questions. One woman in Texas, upon hearing where the drive was bound for, asked: ''don't they already have enough cows in Montana?''
The drive, Austin explains, has no practical purpose other than trying to recapture the spirit of the golden age of cattle-herding that began after the Civil War. Because of a shortage of beef in New York, he says, ranchers in Texas began driving cattle up to railheads in Kansas and Nebraska, where they sold them to shippers for huge sums. Some ranchers also pushed their herds up to Wyoming and Montana, where cows were scarce and pasture was plentiful. Austin estimates that about 10 million head of cattle -- and thousands of cowboys -- made such trips.
Modern trail-rider Bruce Seidel has a mixed view of his old-time counterparts. When he hits a rare stretch of open country -- the kind of place where Indians and buffalo used to roam, Mr. Seidel says the cowboys of yesteryear seem like gods.
But when he and his colleagues pile out of a van at a local truck stop to take a shower, he says, the old-timers suddenly seem ''awful dirty.''
''Those guys never took showers,'' Seidel says. ''That's just nasty to think about.''
Besides, Seidel says, if you ran cattle in the 19th century, people locked their doors and hid their daughters when you came to town. Now, he says, they come to you for autographs, and offer you home-baked pies, cookies, and even fresh socks.
Only partly financed by sponsors and private contributors, the drive is fund-raising along the way by selling posters, bandanas, T-shirts, and McCasland allows anybody with a horse to ride along for $100 a day, a price that includes, the brochure says, ''three meals for you and your horse.''
Although ''outriders'' have to hang back where they can't do any damage, Austin says they all go home with the two things cowboys love most: ''a sore butt and a story to tell.''