In 1958 two teen-age boys acquire a war surplus raft in San Francisco, hop freight trains to Idaho where they've never been, and launch on the Snake River, intent on paddling hundreds of miles to its confluence with the Columbia River. Along the way: they upset, go hungry, hitchhike, meet farm families, invade small Idaho towns, and now and then write their worried parents. After capsizing and losing their shoes and meager food supply in remote...