10 Falls in 1 Hike.
Silver Falls Park in located in Silverton, OR only about an hour drive from Corvallis. It has a beautiful lodge and camping area, a cool restaurant/cafeteria to eat at, and of course a gift shop. There are plenty of short hikes to see the 2 main falls but of course I recommend hiking the full 9 mile loop to see all 10 waterfalls (depending on what season you go)!
Silver Falls isn't a tough loop, a few steep points and gravel every once in awhile- but it's a long walk more than anything. Because you'll want to stop to take pictures of most of the falls, I know I did, it'll take about 4 hours total. There are a few good shady points to stop and eat lunch along the way, but make sure to pack sunscreen because you're in the sun quite a bit!
This loop can be crowded when the weather starts to warm up, because of the lodge and camp sites, but the full 9 mile loop never seems to get too congested. There are a few falls you can walk behind and/or under so pack a bathing suit if you're going in the summer time! Between the waterfalls there are also gorgeous bridges and plenty of greenery, it's a hike that could easily be done with a dog but he must be on a leash because of resort rules.