Reposted comment because I didn't see the rule beforehand about including URLs.

Hi neighbor! If you haven't gone before, I highly recommend rerouting a little bit of your drive to go down Chuckanut Drive in Bellingham. It's not much of a detour time wise, but the views on the drive alone are incredible! Also, Larrabee State Park off of Chuckanut has an incredible beach that is worth checking out if you can. But if you decide to check out the beach, it's a short but steep walk down from the parking lot that isn't accessible to everyone. I hope you have fun on your trip!

A tire store for winter tires if you’re planning on doing this before April

Snoqualmie Falls. Large waterfall just of I-90 in Washington state before crossing Snoquamie Pass. Ten minute detour off of I-90, and it’s free.

Swing north at Missoula to cover Glacier National Park as well if you have the time.

The Hyak Tunnel just past Snoqualmie Pass (if you do it before winter - when that becomes a nordic area). You can walk across the Columbia river on a newly renovated railroad trestle that is part of the Palouse to Cascades Trail. Before you cross the Columbia, you can also check out the Gingko Petrified Forest interpretive center - it some great exhibits about the Great Missoula Floods and petroglyphs that were moved up the the dam flooded the river bank. After you cross the Columbia at Vantage, stop off at the overlook (if it is open) you can climb up to a sculputral exhibition of running horses and get a great view of the river. In Spokane check out the River Front Park. Cool towns along the route include Roslyn (where Northern Exposure was filmed) and Ellensburg. Here is a link to a map centered on the Hyak Trailhead. https://maps.northwestportal.com/outdoors/#14.11/47.393442/-121.388042 This view has the railroad bridge, visitor center and the overlooks (one in each direction) https://maps.northwestportal.com/outdoors/#10.87/46.910251/-119.971950 And here is the map centered on the park in Spokane: https://maps.northwestportal.com/outdoors/#14.92/47.660817/-117.420713

Lewis & Clark Caverns near Three Forks, MT is a good cave tour, if you have time.

Frenchman’s Coulee is a interesting stop on i90, really amazing views of Columbia River Gorge, and a fun climbing stop at the Feathers.

Lewis and Clark caverns 100%. Do it.

Right after crossing Snoqualmie Pass you’ll end up in N. Bend, WA. Stop by Twede’s Diner. It was a prominent location for Twin Peaks. When you are done, you definitely need to see Snoqualmie Falls!

I like Wallace ID, just off 90 for a pit stop, old mining town with some real character.

Drive past Anaconda and you’ll see one of the largest brick smelter chimney left in the world. The park might be opened, was closed last year.

Then Butte MT is a must stop. The downtown is authentic, an old time capsule of when it was a prosperous copper mining town. Then you have to go see the copper pit. The scale is outrageous.

Probably not a must-do, but after the long drive through central WA, I’d recommend stopping in Spokane and checking out riverfront park and/or Manito park. Also couer d’Alene is a nice town too definitely a nice place to get out of the car and walk around at.

Palouse Falls in WA, Craters of the Moon in ID.

I believe there are some interesting ghost towns along the way, MT I think, though snow may become a concern making trips off the highway if you’re not prepared.

You’ll be traveling near/through wine county so you can look for wineries near towns you’re driving through.

Spokane is beautiful. Riverfront Park is worth time to stroll through with restaurants and pubs near by.

A little off the main route, but Lost Trail Hot Springs was nice for a family traveling in an RV.

Surprised no one suggested timing it such that you can drive Cascade Highway instead of I90 in Washington. It’s only open half the year but it is not to be missed (perhaps timing doesn’t work).

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If you are into wine Woodinville

If you like beer the big brewery in Missoula is a good place to stop off.

You also have to stop at 50,000 silver dollar inn because honestly you’ll see so many roadside billboards for hours before hand that you’ll stop anyway to see what it is.

50,000 Silver Dollar Inn in Haugan, MT

You can skip everything else.

Definitely check out the Wheat Montana Farms & Bakery off I-90 just before Three Forks!

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The Mountain Loop Scenic Byway

Deception Pass State Park - Whidbey Island - Ferry to Mukilteo

The Channeled Scablands

Poking around Leavenworth is fun and would be a nice place to get out and stretch the legs

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If you’re into engineering sights the largest building in the world (still? Not sure) is the Boeing factory, and it has a cool tour, and of course the grand coulee dam.

My advice? Bring snacks, water and blankets. Snoqualmie pass gets fucky sometimes. As you pass through Idaho, there are several old mining towns that look straight out of The Wild West. They are good to get off I-90 to stop for lunch and explore. One town we explored didn’t have any cars. It was all dirt bikes, quads, or SxS’s. All throughout the town. Oh and word of warning about Jellystone: The closer you get to the entrances, the costs of food, gas and lodging skyrocket. Load up on beer, gas and food in either Missoula, Butte or Livingston. If you stop in Butte, the Old town is up on the hill, and you can see The Berkeley Pit which is a massive abandoned open pit mine. The lower part is just a bunch of shitty strip malls.

Well since Idaho is considered the Walmart of the PNW, you can certainly skip that.

If you are traveling in April then you should consider stopping in Mt Vernon for the Tulip Festival. There’s a petrified forest state park just before you cross the Columbia on I90 that is an interesting detour. On the other side of the Columbia River there’s a lookout point, Wild Horse Monument I believe, that gives you a good view of the river and is a nice place to stretch your legs. If you have the time you can detour in Montana up to Glacier National Park (I regret not being able to do this on my Yellowstone trip). Since you’ll be in the area I also suggest driving down to the Grand Tetons through the John D Rockefeller Jr Memorial Parkway. If you want to camp in the park make your reservations early, but if you don’t there are campgrounds within reasonable driving distance outside the park, there’s also a pretty nice KOA in Cody, WY (about an hour from the East Entrance). West Yellowstone is right outside the west entrance, so if you want to stay in a hotel outside the park that’s probably the best option. Also, look for the huckleberry vodka in the parks giftshop, it’s delicious! You can also get huckleberry milkshakes in MT and they are delicious!

Fly

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