"The opportunity for a true wilderness expedition experience in the U.S. is slowly disappearing. The best bet you have left is a float down the Tatshenshini-Alsek river system (which does, however, require that you start in Canada). It’s not so much the isolation that makes the standard nine-day to two-week, 140-mile (255-kilometer) trip from Yukon’s Dalton Post to Alaska’s Dry Bay so sublime as it is the scenery."