I did the whole stretch in two days with a rented bike (Spoke N Sport 509-838-8842). The first day, I started at Riverfront Park and went upriver to the Idaho state line (22 miles each way). It's a nice easy mostly flat ride through varied countryside, always along the river. Total elevation gain was maybe 400 feet. The route is well marked and completely on dedicated paved trails and roads. Take plenty of water as some of the water stops are not usable due to contamination. The second day I started at Riverfront Park and went north to Nine Mile Dam. This ride, although shorter (about 12 miles each way) has a little more elevation change (500 feet several times). There are a few hills requiring some effort, but the views are certainly worth it. Get to Maxwell street (runs east west) by heading north from Riverfront Park. Head west and cross the river at the TJ Meenach Bridge and you'll be on the trail. Again, bring plenty of water. Nothing technical here, but it'll get you into the Bowl and Pitcher Loop, among others. Enjoy!