This most northerly of Pacific Maritime ecoregions is composed predominantly of very high elevation ice fields, alpine glaciers and summit outcrops. This ecoregion incorporates part of the largest nonpolar ice fields in the world and includes the highest mountains in Canada. The terrain is similar to that in the adjacent St. Elias Mountains ecoregion (173) but this ecoregion has higher peaks, milder temperatures and receives much higher precipitation as it is on the windward side of the coastal ranges. Although no climate stations exist in this ecoregion, high elevations are estimated to receive up to 3500 mm of precipitation, almost all of it falling as snow. There is no terrestrial vegetation or soil development in this ecoregion. Mount Logan, the highest mountain in Canada at 5959 m asl and King Peak at 5175 m asl are major peaks. A half dozen other peaks exceed 4000 m in height. The Seward, Hubbard, and Malaspina glaciers run from their source areas at high elevation in the ecoregion to tide water in the Gulf of Alaska less than 100 km to the west. Each year, mountain climbers attempt ascents of Mount Logan and the other major peaks during May and June.
This ecoregion is part of the Pacific Maritime ecozone.