The West's desperate water shortage may get a year's reprieve. Last winter's epic snowpack—in some places the biggest since the 1960s— is fueling the best whitewater season since the invention of self-bailing rafts. The timing couldn't be better: 2008 marks the 40th anniversary of the Wild and Scenic Rivers Act. The once-obscure bill, which was signed into law by a war-tainted, outgoing President Johnson in 1968, has protected 165 American rivers from damming and development. To celebrate, we sifted through the country's top Wild and Scenic River trips and picked the best.