The Boise River Greenbelt is 25 miles of continuous paved path running along the Boise River through the heart of the city. It passes through parks, under bridges, past osprey nests and great blue heron rookeries, and connects a dozen different neighborhoods without crossing a single arterial road. Walking, running, and cycling are all popular; in summer, floating the river in inner tubes is a Boise rite of passage.
Access is easy from dozens of points along the route, but Kathryn Albertson Park is a particularly good starting point — a 41-acre wildlife refuge near the western end where Canada geese, wood ducks, and the occasional otter are regular residents. The eastern end near Lucky Peak Reservoir is quieter and more natural. The whole 25 miles can be cycled comfortably in a couple of hours.