The Sacajawea Heritage Trail is a 22-mile contiguous path linking Tri-Cities’ [1] parks. Kennewick’s Columbia Park [2] has a popular six-mile paved, nearly level path, and Richland’s Riverfront Trail offers a shady seven-mile option for biking or in-line skating. Rent bikes from Kennewick Schwinn (3101 W. Clearwater Ave., Kennewick, 509/735-8525).
Links:
[1] http://www.moon.com/destinations/washington/columbia-gorge-and-wine-country/tri-cities
[2] http://www.moon.com/destinations/washington/columbia-gorge-and-wine-country/tri-cities/sights/columbia-park