We drove on 101 from the Rogue River to Astoria on a trip all over Oregon two summers ago. Stayed the night in Bandon, Newport, and Astoria.
The lighthouses are all picturesque and generally easy to access, even with a small kid. Also, they are mostly 15-minute type stops, which works well with a toddler’s attention span. Be aware that sometimes the fog is so thick you can’t see much, still fun though.
The bridges on 101 tend to be good-looking as well, and they all seemed to be different. Not exactly worth stopping and marveling over, but cool nonetheless.
If it says “state park”, “scenic overlook”, “state recreation area” or similar, it’s probably worth pulling over for a walk or at least a quick look-around. Cape Perpetua (near Newport), Devil’s Punchbowl (same), and Ecola (near Cannon Beach) state parks are the only names that come to mind, but we stopped pretty much everywhere and even the worst views were nice. Tidepools, sea stacks, seabirds, unusual wave patterns, etc. Again, very amenable to a small child’s interests and the adults’ desire to get some fresh air and a walk.
Razor clams at the Drift Inn in Yachats. Just sayin’…
Newport is a smallish city with a quaint if a bit touristy waterfront, a harbor full of fishing boats, and a couple of good places to eat. The Oregon Coast Aquarium is in Newport. It’s not huge, but is quite well done. Nearby is the Hatfield Marine Science Center, run by Oregon State U, which has octopuses and a touch tank, among other things. Rogue Brewery is also in Newport, if you like their beers, not sure if they do tours.
Astoria has some nice old buildings, a busy, if kinda touristy, waterfront and the excellent Columbia River Maritime Museum; in addition to the exhibits there is a lightship out at the dock that you can climb around in. A bit further down the street is Josepheson’s Smokehouse, where you can get enough smoked fish to last the rest of your trip.
The Sea Lion Cave, near Florence, is a hoot. Yes, it’s sort of a tourist trap, but it’s one of the good kind. How can you not enjoy a big dark cave with the ocean in it and a ton of loud sea lions hanging out on the rocks? Be aware that you are not actually going to be wandering around in there, it’s more of an overlook from an interior ledge.
The areas in and immediately surrounding Coos Bay and Tillamook seemed kind of boring, but nothing bad.
FYI, all gasoline is full service in Oregon and an unusually large number of businesses do not take American Express.