Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Expedition Opportunities in North America

This is an excellent guide to the wilderness Yukon Rivers, covering 70 runs in the Alsek, Yukon, Liard, and Peel watersheds. The rivers described are class II-V and include several options for muli-day trips. There is also a section on trip logistics including an appendix to air charters.