WHEN the old ``Wyatt Earp'' television series made its debut in the 1950s, it was greeted as an example of the ``adult western,'' a new breed of horse operas more serious than the Roy Rogers and Hopalong Cassidy romps that had dominated the tube.
Grown-up westerns were already established in movie theaters, where filmmakers like John Ford and Howard Hawks had charged them with surprising sophistication. Treatments of the Earp saga in the 1940s and '50s, like Ford's classic ``My Darling Clementine'' and John Sturges's more flamboyant ``Gunfight at the O.K. Corral,'' were enjoyed by moviegoers of nearly all ages.
The genre underwent big changes in the 1960s and '70s, when a wave of revisionist pictures challenged many aspects of the frontier myth; these films showed a social responsibility (``Cheyenne Autumn,'' ``Little Big Man'') and an unromantic grittiness (``McCabe and Mrs. Miller,'' ``The Wild Bunch'') that westerns had never known before. More conservative attitudes returned in the more conservative '80s, and remain in the '90s with all-in-fun epics like ``Maverick'' and old-guy-strapping-on-his-gun adventures like ``Unforgiven.''
The new ``Wyatt Earp'' movie stars Kevin Costner in the title role. Since he rehabilitated the screen image of native Americans in ``Dances With Wolves,'' a rare '90s western concerned with social issues, one might have expected a similarly progressive agenda this time around.
The auteur of ``Wyatt Earp'' is not Costner but director Lawrence Kasdan, however. His idea of a good western is a straightforward clean-up-the-town story - like ``Silverado,'' which he made with Costner nine years ago - sporting a maximum of nostalgic images and a minimum of thoughtful themes.
Kasdan is capable of insightful filmmaking, as he proved in ``Grand Canyon.'' But he puts his imaginative notions back into the holster when he gallops into Old West territory, preferring largeness of scale to boldness of conception. ``Wyatt Earp'' runs well over three hours, and while it's full of action-packed twists, it has only about three ideas to propel it.
The tale begins just after the Civil War, when Wyatt is a boy and the Earp clan goes West in search of new opportunities. Wyatt's dad states the major motifs of the movie in a couple of speeches about family values and self-protection. Blood is thicker than water, so treat everyone outside your family as a stranger. And if you get in a fight with a bad guy, be sure to kill him before he kills you.
Wyatt tries to live peaceably as a young man, but the frontier is short on law and order, and he soon starts obeying his father's lessons. His derring-do lands him a job as deputy marshal, and he keeps Dodge City reasonably quiet until the tragic death of his wife transforms him into a trouble-making drunk.
Later he reforms and gets back into the peace-officer business, dispensing justice with help from his brothers and the notorious Doc Holliday, who has given up dentistry for various forms of hustling. Wyatt also finds time to fall in love with one woman, take another as his common-law wife, and feud with a couple of violent gangs, before the O.K. Corral shootout changes his life forever.
This is standard plot material in most respects, and Kasdan has done little to make it seem new. Fans of time-tested formulas may applaud his fidelity to the genre, but others will wish he'd come up with a few original notions to energize this very long picture.
The movie's old-fashioned approach brings liabilities of its own, moreover. In resurrecting the most conservative form of the western, Kasdan has also resurrected some of its more regrettable conventions, such as its glorification of gunplay and vigilante justice. Also unfortunate is its treatment of female characters, who - with the partial exception of Josie, the hero's third wife - either remain ciphers, with tiny roles in the story, or serve as stumbling blocks to Wyatt's career, by dying young or retreating into pathetic helplessness.
On the plus side, ``Wyatt Earp'' is smartly acted by Costner along with Gene Hackman as Wyatt's dad, Dennis Quaid as Doc Holliday, and Bill Pullman as Bat Masterson's nicer brother. Joanna Going does well as the feisty Josie, and while the screenplay gives the other actresses little to work with, some manage to make their talents visible - notably Annabeth Gish as Wyatt's first love, Mare Winningham as the prostitute he lives with, and Isabella Rossellini in the improbable role of Doc Holliday's wife.
The film is handsomely photographed by Owen Roizman, who knows how to fill the screen with a magnificent vista. Ida Random designed the production and James Newton Howard composed the syrupy score. Kasdan wrote the screenplay with Dan Gordon.
* ``Wyatt Earp'' is rated PG-13 for violence, vulgar language, and some sexuality.