Help what to do in 3 weeks travelling from Seattle - Yellowstone-Seattle

Hi
Hoping for help!!!!! This will be our 3rd road trip this year.... But feel this one I want to do maybe 2 much. We arrive 27th and leave 17th July. The main reason for the trip was to spend time in Yellowstone and see Mount Rushmore however my partner would like to see Salt Lake City. We also love the 4th July celebrations and are interested on where we should be to enjoy them. At present my partner thinks Mount Rushmore is just too far away so the plan for now is :
27-30 Seattle
31 Spokane
1 Bozeman
2 billing
3-6 Yellowstone
7-8 salt lake
9 Boise
10.....
11......
12-14 Portland
15 back to glasgow, Scotland

So far from reading on this forum we are looking at seeing space needle, Boeing factory, underground town, snoqualmie falls, grand couple dam, bear tooth highway, Idaho falls, Shoshone falls and caves, Bruneau dunes and canyon, glacier np, earthquake area, wild horse monument, rodeo in Cody
What do you think..... Can I get to badlands, devils tower and Mount Rushmore so wanted to see these.... Should we miss salt lake as we have seen Death Valley 2 years ago ...... Any thought on how to get the most out of our stay?
I'm 35, my partner is 32 and my son is 15..... We normally try to put in a theme park or two for my son

Ceud mìle fàilte! Welcome aboard the RoadTrip America Forums!

I've had RoadTrips where I was always on the move from one sight to the next, and RoadTrips where I settled down in one location for several days to a week at a time, and I've thoroughly enjoyed both, So whether your current plans suit you is entirely up to you. You can certainly fit it all in to three weeks since even including the Mount Rushmore area with everything else you've listed requires would require about six days of solid driving leaving two full weeks at various locations along the way.

One way to look at this trip would be as a few three-night stops in special locations combined with intervening RoadTrips where the emphasis would be more, but not totally on covering ground. Personally, I'd make my longer stays in Seattle, Yellowstone, and Portland. Each of those places has enough to fill two to three days without any difficulty and that would still leave you roughly a week's worth of time to 'sprinkle' amongst all the other places you'll be driving to. Seattle in particular would be a good place to take it easy at first and get over your jet lag before hitting the road.

Now, besides the places you've listed, here are a few others to consider for your traveling portions: the town of Coeur d'Alene ID and the surrounding scenic byways; the National Bison Range National Wildlife Refuge outside Moiese MT; Little Bighorn National Battlefield; Jewel and Wind Caves; the Crazy Horse Memorial; US-89 south from Yellowstone to Salt Lake City; (Aside: Ignore the warning signs as you drive into Bruneau Canyon about 'objects falling from planes'. You'll be driving through an Air Force Bombing range!); the Historic Columbia River Highway (old US-30); the Rose Test and other gardens in Portland; the sites of the Lewis and Clark National Historic Park; and Olympic National Park.

AZBuck