Mount Thompson is named for Charles Sproull Thompson (1869-1921) who participated in numerous first ascents in the Canadian Rockies. In August of 1897, Charles Thompson, Hugh Stutfield, and J. Norman Collie camped on the shores of Bow Lake; then proceeded to climb the Bow Glacier, which at that time descended farther down into the valley; then crossed the Wapta Icefield to attain the summit of Mount Gordon. From Mount Gordon they were surrounded by unnamed mountains and named one of them Mount Thompson. The first ascent of Mount Thompson was made the following year (1898), by Norman Collie, Hugh Stutfield, and Herman Woolley. The mountain's name became official in 1928 by the Geographical Names Board of Canada. Charles Thompson named Portal Peak which is a subsidiary peak located 1.5 km southeast of his peak. Portal Peak flanks one side of Bow Glacier, which in 1897 was considered the portal to the Wapta Icefield.