Along the western edge of Glacier Bay National Park flows the Tatshenshini River, considered one of the world’s premier wilderness rafting routes. Bears, moose, mountain goats, and Dall sheep are all visible along the way. The river rolls through Class III white water and spectacular canyons along the way to its juncture with the Alsek River.

Alaska Discovery (510/594-6000 or 800/586-1911, www.akdiscovery.com) has several trips each summer down this spectacular route, as well as down the more remote Alsek. A 12-day river-rafting trip on the Alsek isn’t cheap at $4,100, but the price includes a van ride from Haines to the put-in point at Dalton Post in Yukon, and a spectacular helicopter portage around the Class VI rapids of Turnback Canyon.

One of the real treats of this trip is paddling past the seven-mile-wide Alsek Glacier. The trip begins in Haines and ends in Yakutat.

Other good companies offering Alsek and Tatshenshini trips include Chilkat Guides (907/766-2491 or 888/292-7789, www.raftalaska.com) and Canadian River Expeditions (867/668-3180 or 800/297-6927, www.canriver.com). Contact the park (907/697-2230, www.nps.gov/glba) for details on running the rivers.