The White River Ash blasted from giant eruptions somewhere in today's Wrangell-St. Elias Mountains, drifted as far away as Ireland and Germany... Ash from the White River eruptions, possibly from 15,638-foot Mount Churchill or at least close to it, left an easy-to-see mark on eastern Alaska and northwestern Canada. Explorer Frederick Schwatka documented the ash in 1885 in his book "Along Alaska's Great River." People driving the Klondike Highway pass more than two feet of the whitish grit exposed in road cuts on their journey through the Yukon Territory... Froese and Jensen traveled in the Yukon to a branch of...