In the summer of 2006, four old men began an adventure that took them from the suburbs of Washington State through British Columbia and Alberta to Great Slave Lake in Canada's Northwest Territories. In two canoes, they began a 900-mile (1,500 km) journey down the Mackenzie River. One month later, they reached the town of Inuvik near the Arctic Ocean. Perseverance: One Month Canoeing on the Mackenzie River is a memoir of that journey told by one of...