Portland, or to yellowstone in August

My family and I are planning a road trip from Portland, OR to Yellowstone this August. We're going by way of Spokane there and Boise on the return. We have 2 teens and a 10 year old that we want to keep entertained (with as few electronics as possible). Anyone have any suggestions of quirky roadside attractions? I'm thinking largest ball of yarn or some odd destinations in between. I thought these little surprises could perk them up. 1st day we're driving Pdx to Missoula, 2nd Missoula to northern entrance and staying the night, 3rd to Cody (going through the park and leaving NE entrance), 4th Cody (entering through East entrance to West Entrance and stay 2 nights, 6th day drive to Boise and stay the night then home.

I've only got a few possibilities for you but the experts here will almost certainly have a lot more.

I guess you know about the Stonehenge replica at Maryhill, with its excellent view over the Columbia River.

North of Missoula, Montana there's the National Bison Range (i.e. buffalo) but of course you're likely to see some of those magnificent beasts in Yellowstone.

At Twin Falls, Idaho there's a huge steel arch bridge over the Snake River canyon (it carries the road between I-84 and the town), well worth a stop to view.

Near Baker City, Oregon there's an excellent Oregon Trail museum.

Welcome aboard the RoadTrip America Forums!

I've done some RoadTripping along both of your proposed routes to/from Yellowstone and obviously you and your children are in for a treat. On the northern route through Coeur d'Alene, you can start by reviewing this RoadTrip Report of a drive I took in the Palouse and Coeur d'Alene area. From there to Yellowstone, your teens might like a stop at the Grant-Kohrs Ranch National Historic site or one of the several mining museums in and around Butte.

On the return trip a few more 'surprises' come to mind. Early on the first day there's Craters of the Moon National Monument, while near the end of the day you'll be near both Bruneau Dunes and Bruneau Canyon. The latter is particularly quirky since as you drive in on the only road to it, there is a sign warning you about 'objects' falling from planes. You are perfectly safe, but you are driving across an Air Force bombing range. On the second day, there is the Oregon Trail Interpretive Center in Baker City OR, and a unique memorial in Maryville WA on the north shore of the Columbia River

AZBuck