Edmund Thomas Coleman, an Englishman who resided in Victoria, British Columbia, Canada and a veteran of the Alps, made the first attempt to ascend the mountain in 1866. He chose a route via the Skagit River, but was forced to turn back when local Native Americans refused him passage
Later that same year, Coleman recruited Whatcom County settlers Edward Eldridge, John Bennett and John Tennant to aid him in his second attempt to scale the mountain. After approaching via the North Fork of the Nooksack River, the party navigated through what is now known as Coleman Glacier and ascended to within several hundred feet of the summit before turning back in the face of an "overhanging cornice of ice" and threatening weather. Coleman later returned to the mountain after two years. At 4:00 p.m. on August 17, 1868, Coleman, Eldridge, Tennant and two new companions (David Ogilvy and Thomas Stratton) scaled the summit via the Middle Fork Nooksack River, Marmot Ridge, Coleman Glacier, and the north margin of the Roman Wall.