When Echo River Trips asked Vladimir Gavrilov, who literally wrote the book on Russian whitewater (Rivers of an Unknown Land), to lead a trip on his favorite river, expenses be damned, he picked the Kaa-Khem. The 166-mile float begins with an Mi-8 helicopter dropping you in the heavily forested southern province of Tuva, 50 miles north of the Mongolian border. With its vodka-clear waters, exceptional fishing, and swift current—one particularly rambunctious ten-mile section of river offers more than 30 Class III and IV rapids—the Kaa-Khem is reminiscent of the Middle Fork of the Salmon. Except for its location: near the geographic center of the Asian subcontinent, about as far from an ocean as you can get. Then there are the fish. The Kaa-Khem is home to both feisty grayling and harder-to-find taimen, leviathans that feed on mice and that Vlad and his buddies try to land using fur-wrapped pieces of wood with huge hooks. $5,660; July 24–August 7; echotrips.com.