ONE OF THE FOUR CHEYENNE MEN BEING PROSECUTED FOR THE DEATH OF A HIGH-RANKING BULL RIDER HAS ENTERED A GUILTY PLEA. 26-YEAR-OLD RHETT EPLER WAS ACCUSED OF SUPPLYING DRUGS WHICH LED TO THE DEATH OF 21-YEAR-OLD BRYAN GUTHRIE. HE IS ONE OF FOUR MEN FACING FEDERAL CONSPIRACY CHARGES TO DISTRIBUTING COCAINE AND HEROIN. EPPLER'S PLEA AGREEMENT STIPULATES HE MUST TESTIFY AGAINST THE OTHER DEFENDANTS. GUTHRIE RANKED AS HIGH AS THIRD LAST JANUARY IN THE PROFESSIONAL RODEO COWBOYS ASSOCIATION. A SECOND MAN, 22-YEAR-OLD JOEL MURDOCH, MAKES HIS APPEARANCE TOMORROW AFTERNOON.