The glowing emerald of Treasure Valley began as an ambitious plan in the 1960s to prevent development in the Boise River's floodplain and provide open space in a rapidly growing city. Today the growing collection of parks and museums along the tree-lined riverway is connected by more than 30 miles of multiuse paths, and hosts an insanely popular summer floating scene. A white-water park, complete with hydraulically controlled waves, is one of the largest in the country.

　　The put-in point for tubing the river is Barber Park, 6 miles east of downtown. It's a 5-mile float to the take-out point at Ann Morrison Park. There are four rest stops en route and a regular shuttle bus ($3) takes you back to your car from the take-out.

　　The most central and action-packed space on the Greenbelt, 90-acre Julia Davis Park contains the Boise Art Museum and is the permanent location of the Idaho State Historical Museum (temporarily closed for renovation).