The Cordilleran ice sheet was a major ice sheet that periodically covered large parts of North America during glacial periods over the last ~2.6 million years. This included the following areas:

• Western Montana
• The Idaho Panhandle
• Northern Washington state down to about Olympia and Spokane
• All of British Columbia
• The southwestern third or so of Yukon Territory
• All of the Alaska Panhandle
• South Central Alaska
• The Alaska Peninsula
• Almost all of the continental shelf north of the Strait of Juan de Fuca