after months of monotonous work, dull food, and abstinence of all kinds, were paid off and turned loose. They howled, got shaved and shorn, bought new clothes and gear. They drank "white mule" straight. Madams and gambling hall operators flourished in towns that were wide open twenty-four hours a day. Violence and ebullient spirits called forth a kind of "peace officer" that cattle towns made famous—the town marshal. James Butler Hickok, Wyatt Earp, and Bat Masterson were among the best-known cattle town marshals. The number of killings was, however, small by the standards of eastern cities. End of the open range Expansion of the cattle industry resulted in the need for additional open range. Thus many ranchers expanded into the northwest, where there were still large tracts of unsettled grassland. Texas cattle were herded north, into the Rocky Mountains and Dakotas. In 1866, Nelson Story used the Bozeman Trail to successfully drive about 1000 head of Longhorn into the Gallatin Valley of Montana. Individual cattle barons such as Conrad Kohrs built up significant ranches in the northern Rockies. In 1866, Kohrs purchased a ranch near Deer Lodge, Montana from former Canadian fur trader Johnny Grant. At its peak, Kohrs owned 50,000 head of cattle, grazing on 10 million acres (4 million hectares) spread across four states and two Canadian Provinces, and shipped 10,000 head annually to the Union Stock Yards in Chicago. Later, however, continued overgrazing, combined with drought and the exceptionally severe winter of 1886–1887 wiped out much of the open range cattle business in Montana and the upper Great Plains. Following these events, ranchers began to use barbed wire to enclose their ranches and protect their own grazing lands from intrusions by others' animals. In the 1890s, herds were still occasionally driven from the Panhandle of Texas to Montana. However, railroads had expanded to cover most of the nation, and meat packing plants were built closer to major ranching areas, making long cattle drives to the railheads unnecessary. Modern cattle drives Smaller cattle drives continued at least into the 1940s, as ranchers, prior to the development of the modern cattle truck, still needed to herd cattle to local railheads for transport to stockyards and packing plants. Today, cattle drives are primarily used to round up cattle within the boundaries of a ranch and to move them from one pasture to another, a process that generally lasts at most