Although previous surveys assigned an elevation of 10,850' (3307 metres) to Mount Warren, Bill Corbett, author of "The 11,000ers of the Canadian Rockies," used his gps to record a "conclusive reading" of 11,030' on the summit in 2007. Recalling the naming of this mountain, Mary Schaffer wrote, "Next rose a magnificent double-headed pile of rock, whose perpendicular cliffs reached almost to the shore...It was its massiveness, its simple dignity which appealed to us so strongly, and we named it Mount Warren, in honour of 'Chief,' through whose grit and determination we were able to behold this splendour." Billy Warren was Mary Schaffer's packer and chief guide and later became her second husband. Regarding his skills as a guide she wrote, "There are older ones (guides), there are better hunters, perhaps, with wider experience in forest lore, more knowledge of the country, but for kindness, good nature (such a necessary adjunct), good judgment under unexpected stress, he had no superior." In 1950 the lower, easterly peak of Mount Warren was assigned the name Monkhead Mountain because of the "cowl-like look of the summit."