July 16 – On this day in Montana history in 1806 the William Clark and part of the Lewis and Clark Expedition, which had split up on its return trip, crossed the Bozeman Pass and began its descent on what is now known as the Yellowstone River. Clark reported in his diary that the current was rapid on the ”Rochejhone.” He was busy looking for a large cottonwood tree so that he could build a canoe that could navigate the water.