When Ennis and Jack first meet, they won't even speak to each other. They wait for the owner of a sheep ranch, anticipating his return so they can ask for whatever work he has to offer in the outback of Wyoming, circa 1963. Even when they are hired to work together, they only slowly become friends until one freezing night in the mountains. When they can't help but share a tent, they suddenly, frantically sex.

They would surprise us, too, but "Brokeback Mountain" has long since been pigeonholed as the "gay cowboy movie," a distinction that would be as disturbing to the characters as it will be to audiences who see the film and experience its searching, tender, almost tragic story of love and loss.

The film, expanded from the famous Anne Proloux short story, is headlined by two relatively big-name stars - Heath Ledger and Jake Gyllenhaal - who step over the potential for controversy and completely immerse themselves in their roles. The frankness with which the film deals with its same-sex romance (and, yes, graphic sex) demands not only the respect of the audience but also its undivided attention. There is scarcely a moment where viewers' preconceived notions can play out because the romance's onscreen intensity always feels so urgent.

But then again, so does the entire film. Directed by Ang Lee, the Taiwan-born great who previously delved into genre filmmaking with such modern touchstones as "Sense and Sensibility," sees "Brokeback Mountain" as a classic American western, casually brooding and always visually breathtaking.

Lee develops the love story in much the same way: No issue is made of sexuality other than the way it affects the characters, as their clandestine romance survives two long decades and both men's marriages even while their constant separation slowly chips away at them until they finally can't take it.

The remarkable thing about the film is that Lee constructs it very much as a product of these two genres - the western and the sweeping period romance - and has no qualms about its deviation from their conventional terms. This is brilliantly crafted work, without question one of the best movies of the year.

This would amount to little, of course, if the stars weren't up for their roles. As Ennis Del Marr, the film's aching backbone, Ledger delivers the performance of his career. The actor, otherwise best known for roles as tween heartthrobs in films like "A Knight's Tale," renders a performance so mesmerizing and haunting that it dominates the film. Gyllenhaal doesn't always follow through in the final act but still shows the work of a thoughtful and skilled performer. As the men's wives, Anne Hathaway ("The Princess Diaries") and especially Michelle Williams (TV's "Dawson's Creek") are honest, simple and powerful, aware of their husbands' secret to varying degrees but always sensing the emotional distance.

"Brokeback Mountain" ends with a tinge of hope, but the film is really about loss in more complex terms than you might expect. The men live in a time when their love was dangerous; they don't understand it and they don't want to, but they can't escape it. I have no idea whether the film has the power to change minds as its early champions have claimed. But I do know that it's moving and provocative, and audacious enough to follow through with its convictions without the slightest hint of hesitation. This is a new Hollywood classic in a very traditional sense, the sort of film with images that will forever ingrain themselves in the industry's creative imagination if only for the subtle revolution they represent.

Rating: 4.5 out of 5 stars