As miners flocked to the West, the US government assisted their efforts by building the Bozeman Trail to link the mining towns with the East. The trail, however, encroached on Sioux Indian hunting grounds, and Chief Red Cloud (1822-1909) warned that it would not be tolerated. For Phil Kearney was built to guard the trail in northern Wyoming, but the Sioux frequently attacked US troops. When a work force from the fort was set upon, an 82-man force under Captain William Judd Fetterman (ca. 1833-66) was sent to its rescue. Once outside the fort, Fetterman's party was lured into a trap by about 1,500 Sioux under Chief High Backbone (fl. 1860s) and massacred on December 21, 1866. Parts of the Bozeman Trail were closed afterward.