Fort Elizabeth Meagher, named for the wife of Thomas F. Meagher, secretary and former acting governor of the Montana Territory, was established in May, 1867 eight miles east of the town of Bozeman, Montana at the mouth of Rocky Creek by Brigadier General Thomas Thoroughman and Colonel Walter W. De Lacy of the Montana Territory Volunteer Militia. The post's mission was to provide settlers protection against hostile Crow and Sioux Native Americans who were expected to invade the area following the murder of John Bozeman in April, 1867. The main post stockade, and a picket-post erected on the approaches to Bridger Pass, were designed to block the passes through the mountains into the valley.