After competing in The Cheyenne Days celebration, Leland Martin Rich, known as "Wyoming Jack," and his four brothers accept a job driving a herd of cattle 115 miles from the small Wyoming town of Deaver to Thermopolis, Wyoming. Their adventures begin when the local sheriff informs them that two of his wranglers are convicted felons. Jack agrees to keep a sharp rein on them, but this is only the first of many challenges on this danger-filled cattle drive. At Lobo Pass, they hear the first wolf cry. A dying calf was killed to use as bait to lure in wolves. Just like clockwork, the pack settles...