THE COWBOY had sunk about as low as he could go -- down to singing "Home on the Range" in French to sell yogurt. It looked like nobody -- not even Clint Eastwood -- could save him. But then along came Lawrence Kasdan, a stranger naturally.

The man who made "The Big Chill" and "Body Heat" and wrote the original script for "Indiana Jones" now wins with a western. "Silverado," with its open spaces and heroic faces, resurrects America's mightiest myth.

Kevin Kline, Kevin Costner, Scott Glenn and Danny Glover star in this exhilarating comic western as four horsemen who hook up on the road to Silverado, out-riding, out- gunning and out-funning assorted sidewinders along the way.

Music swells, bullets fly, horses stride neck and neck, their manes to the wind, as the riders gallop toward the future, leaving the scrub behind. Ah, manifest destiny. Ah, four John Waynes.

Kline, as at home in the west as he was in "Sophie's Choice," is an easygoing drifter with a quick draw and an enigmatic smile. And Glenn is the classic loner, a squinty-eyed rifleman with skin dried like jerky.

Costner plays his brother Jake, a fearless '50s-style cowboy who can twirl his guns faster than a weathervane in a Texas tornado. Jake's a daredevil, a trick-rider, the kid with a toy gun in every one of us.

Costner deserves this shot more than anyone. His last role for Kasdan was Alex in "The Big Chill," where his scenes, except as the corpse, were cut. Here he gives the liveliest performance you've ever seen, stealing the show with his antics and big, floppy smile.

Unlike his costars, Glover has no stereotype to parody here, what with black screen cowboys so scarce. But Glover, familiar as the sharecropper of "Places in the Heart," sets a welcome precedent as a quiet two-fister, a loner by historic necessity.

Jeff Goldblum, Brian Dennehy and John Cleese have lesser roles as a gambler, a crooked sheriff and another crooked sheriff. Cleese, mightiest of the Pythons, is purposefully out of place, and hilarious here. "As you have probably guessed," says Cleese emphasizing the absurdity, "I'm not from these parts."

True to the genre, women figure peripherally, with Rosanna Arquette appearing as a hardy pioneer and Linda Hunt as a feisty saloon keeper. A murky, seemingly sexual relationship develops between Kline and Hunt, but it doesn't much matter -- there's more chemistry between him and his horse.

The diminutive Hunt, however, does deliver The Speech, the moral behind the story: "Some people think they can push you around if they're bigger and meaner. But only if you let them." It's the theme of the summer, it seems, in "Rambo" and to a lesser degree in "Back to the Future." Push back. And push together.

They say you can interpret the mood of the country by the way it treats its cowboys. And it looks like America is sitting tall in the saddle again.

SILVERADO (PG-13) -- At area theaters.