Yes… as a matter of fact, where I live in Albany, OR we are actually right in the middle of an awesome scenic bikeway. I actually have a B & B there and we get bicyclists from all over the world stay with us because of our location. Check out this site, and we often have guests ride our covered bridges that begin just a few miles from Albany. You can certainly find shorter distances within these rides and many areas offer flat riding areas. That happens to be why our scenic bikeway and covered bridge area in Linn County is so popular.
Also, many people ride the bikeway just partially let’s say from Albany to Eugene and then take the train back to Albany for example. Amtrak has a great schedule and is a great resource for our bicyclists wanting to ride only a portion. You can certainly just enjoy a ride around one of our towns such as Corvallis! It’s all flat and riding to Oregon State University and around the downtown will offer you some great sites. There’s even a bicycle renting shop downtown if you aren’t bringing your own. They are all super nice and helpful.
Hope this helps!