A new film by Ang Lee tells the tale of a homosexual love affair between a ranch hand and a rodeo rider. But what is life really like for America's gay cowboys? Jamie Wilson travels to Dallas to find out.

Chuck Browning's face is a picture of concentration as he squeezes his legs around the animal's flanks and wraps the rope tightly across his palm. As the gate swings open, half a tonne of snorting, kicking, stamping bull launches itself into the ring, contorting itself in an attempt to unhinge its perilously secured passenger. The bull bucks and kicks, and Chuck clings on like the 10-time rodeo champion he is, his right hand high in the air in the classic bull-riding pose. When a hooter sounds, Chuck throws himself clear, rolling over as he hits the dirt to prevent the bull skewering him with its horns. Then he picks up his black Stetson hat, dusts himself down, raises an arm in salute to the cheering crowd, leaps over a gate in the 6ft-high iron fence that surrounds the ring - and lands in the arms of an equally tough looking man.

Hugging is a common sight at the International Gay Rodeo Association finals, where cowboys like cowboys, cowgirls like cowgirls and the drag queens can wrestle a kicking steer to the ground in six seconds. This year's rodeo is taking place at the Resistol Arena in Mesquite, a dusty industrial suburb on the east side of Dallas where the city meets the prairie. From the outside, the concrete, 5,000-seat arena does not look like much, but for rodeo fans it holds the same degree of mystique and allure that Wembley does for football supporters. It is known as one of the last bastions of the old west, where real cowboys go to watch bull-riding and steer-roping. For the International Gay Rodeo Association (IGRA) to have been allowed access this year to its hallowed dirt floor for the first time is a signal that finally - even if they are not exactly being embraced by the straight cowboy community - they are slowly being accepted.

The west is a land deeply rooted in conservative history and ideals, and what goes on openly in New York and Los Angeles only happens in cowboy country well behind closed doors - and, according to some of the competitors, beside remote campfires.

But next month a new film by Oscar-winning director Ang Lee will tackle the previously taboo subject of homosexuality out on the range. Brokeback Mountain, starring Heath Ledger and Jake Gyllenhaal, begins in the 1960s and traces the love affair between a ranch hand and a rodeo cowboy. Based on an Annie Proulx short story that first appeared in the New Yorker, Brokeback Mountain recounts how the pair go their separate ways and end up both getting married to women. Four years later they meet again, and their relationship is secretly rekindled. Earlier this year the film picked up the top award, the Golden Lion, at the Venice film festival. The Calgary Gay Rodeo Association advised on the production and appears in several sequences, and for many at the gay rodeo finals - who are able to enjoy an advanced screening of the film - the plot has uncanny similarities to their own lives.

John Beck, 56, one of the founding members of the IGRA, knows all about the prejudice of being gay in rural America. He grew up in Nebraska, surrounded by "John Wayne types"; the only problem was that from an early age Beck knew he was gay. As a young man he had had numerous liaisons with men, but did what many gay men of his generation felt forced to do: he married a woman. After four years, Beck's wife found out that he was gay. She left him and told her family about his secret. His sister in law couldn't wait to tell the whole town and he spent the next nine months sleeping with a shotgun as his companion. "First of all the barn caught on fire mysteriously, then I had 'Leave or die' written in blood on the windshield of my car," he says. "One night I just decided I had to leave. It was November, the snow was blowing, and I got out to the end of the drive and flipped a coin. The coin was either going to be heads Denver or tails Florida. Well, I went to Denver and I been there ever since."

Arriving with only $80 in his pocket he tried to scratch out a living doing odd jobs, but probably would have left if he had not found the Colorado Gay Rodeo Association. Most gay cowboys end up having to move to the city, and as a result they have to leave their work with horses behind. But the gay rodeo allows them to keep that connection.

The IGRA is now the second-largest organiser of rodeos in the world, putting on events across the US and Canada, and raising millions of dollars for charities at the same time. It is all a far cry from the first gay rodeo that took place near Reno, Nevada, on October 1 1976. It was organised as a charity event by a local gay association looking to raise money to put on an old peoples' Thanksgiving dinner and had taken more than a year to organise: they were repeatedly refused permission to use local showgrounds and then could not get any ranchers to allow gay people the use of their animals. Finally, they were able to locate five "wild" range cows, 10 "wild" range calves, one pig and a Shetland pony. More than 125 people took part in the first event and there were three winners: "King of the Cowboys", "Queen of the Cowgirls" and "Miss Dusty Spurs" (the drag queen).

Over the next decade local gay rodeo associations were formed in Colorado, Texas, California and Arizona. As the movement grew - there are now 24 associations that compete under the IGRA umbrella - rules for the rodeos were ratified and the season now culminates in the IGRA Finals Rodeo, where the top 20 contestants in each category compete for the title of international champion. Most of the events at the gay rodeo are the same as for any rodeo - bull-riding, roping events in which competitors lasso moving steers (castrated bulls) from horseback, and traditional speed events where riders negotiate their horses through tight turns around barrels and poles. But it also includes "camp" events such as wild drag racing, where a man and a woman push a steer into the arena and a third competitor dressed in drag has to get on board to ride it over the finish line, and goat-dressing, in which partners chase down and then put underwear on a tethered goat. "I guess these are the events that make our rodeo more fun to watch," the president of the IGRA, Brian Helander, says from the stands, while two men in the ring grab a goat by the hind quarters and give it what might be termed - in schoolboy parlance at least - a very severe wedgie.

Gene Fraikes, 43, prefers the more macho events, but then he has never really seen himself as a "nelly" (as he puts it). In fact, until about eight years ago he didn't think he was gay at all. "The media portray gay men as being very feminine and flamboyant. Growing up in a small town in rural Illinois, I never saw a gay person portrayed in any other way, and I thought, well, that's not me.

"I used to make up excuses to go away on fishing trips. I found out that I could hook up with men if I hung around the right places ... It caused a lot of grief for me emotionally. But even at that time I had real doubts that I was gay. Even after my wife found out I was having sex with other men, I swore blind that I wasn't. We were together for five years after it came out. But I swore to her I wasn't gay because I really didn't think I was."

Finally, with two children and four grandchildren, Fraikes accepted that maybe he wasn't straight either. "It was only when I went on the internet and I was invited to Dallas, and I saw men holding hands, I suddenly realised that there was a whole different world out there ..."

Fraikes is a "chute dogger", which means he wrestles steers. Wearing a Kevlar vest to protect him from the steer's razor-sharp horns, he climbs down into the bull pen. The aim is to drag the animal over a line in the dirt and then bring it to the ground as quickly as possible. To do this Fraikes grabs the steer by the head, putting one hand around the animal's neck and taking a firm hold on one of its horns with the other. Satisfied with his grip, he shouts, "Pull", the gate swings open and the two stumble out of the chute as if they are roped together. Half dragging and half pulling the steer over the line, Fraikes turns its head towards the sky while, at the same time, leaning down with all his weight until the animal falls, almost gracefully, to the ground and the judge sounds a whistle to signal the end of the bout.

It looks simple, but it can easily go wrong. A scar on Fraikes's cheek can vouch for that, the result of a bucking steer ramming him in the face and puncturing his sinus with one of its horns. As he picks himself up and the chute crew corral the steer back into the pen behind the arena, he is greeted by Frank Mazzo, a 46-year-old West Virginian who has been his partner for more than five years. Together they walk behind the stands, past stalls selling scented candles - "You won't find these at a straight rodeo," says one of the stallholders - and T-shirts with the logos "Forget the Bull - Ride the Cowboy" and "I've Been A Bad Cowboy. Send Me To Your Room." "I told you it was a different world," Fraikes says.

Dennis "Squeaky" Terrell comes from a family steeped in cowboy history and folklore. His father and grandfather worked on the legendary King Ranch - 825,000 dusty acres of land on the Wild Horse desert between Brownsville and Corpus Christi in Texas that is known as the birthplace of the American ranching industry. He says he was born with a rope in his hands, and has been riding for longer than he has been able to walk. And he has also known he was gay for as long as he can remember. "I just knew that there was something. Even at the age of eight or nine I thought all my dad's friends were just ... But growing up the way I did, I didn't even know there was such a thing as gay. I had girlfriends but hated having sex with them."

While it might not be talked about and it certainly isn't accepted, according to Squeaky homosexuality has always been at home on the range. "Of course it is part of the cowboy way of life," he says. "It has to be. All those men out there together. When I was in my late teens, I would be loaned out to the bigger ranches, and a couple of times stuff would happen in the bunkhouse with older men. But the thing is, it was never, ever talked about. Not during and not after." Was he scared? "It was more scary being with a woman, which just didn't feel natural."

The one thing that did scare Squeaky was his family finding out. "I guess I figured my family would disown me. Even now it's not something I've ever told them. I know they know I'm gay, but I've never talked to them about it."

He believes that if he hadn't met his best friend and rodeo partner, Andy Anaya, he would have done what so many other gay cowboys did and got married. Squeaky and Andy are professional rodeo stars, riding on both the regular and the gay circuit, and they are pretty much the best in the business. Watching the pair work together in the team roping event - a fiendishly difficult challenge involving lassoing the head and back legs of a steer while, at the same time, trying to avoid high-speed collisions, entanglements and even loss of fingers - is quite breathtaking.

They have never been an item - and only found out the other was gay when they turned up in the same gay bar while competing at a regular rodeo. "You should have seen the look on his face when I tapped him on the shoulder," says Squeaky as they lounge on the back of a flat-bed truck outside the arena. For years it was their secret, but Anaya gave Squeaky the confidence not to conform. They would compete on the regular rodeo circuit using different names from the ones they used on the gay circuit. "Man, when we started, we would have been run out of town if they knew," he says. "But we came out about three years ago. It got to the point where I didn't care, I was sick of hiding my life. It was weird; all the young cowboys were completely cool with it. But we had been riding in rodeos for years and we had proved ourselves. We were in the top 15 in the world, so they couldn't just write us off as a couple of queens. We got their respect first."

"Cowboying ain't just for straight guys," says Lonnie Miller, another Texan ranch hand who is competing in the rodeo. He adds with a grin: "Andy and Squeaky - I'd put them up against anyone, they'll spank any straight guy's butt"

Brokeback Mountain is released in the US on December 9 and in the UK on December 30