July 17 – On this day in Montana history in 1860 Capt. John Mullan reached the summit of the Continental Divide west of what is now Helena. He had first been at this point six years before on a survey trip for the U.S. Army. This time he had a road building crew with him that was laying out the first  overland route between Fort Benton – the terminus of Missouri River boat traffic – to Walla Walla and the gateway to the Columbia River. The pass is now known as Mullan Pass in his honor. The next day the crew experienced a solar eclipse.