They go from Denver to Pikes Peak, then to Great Sand Dunes, to Gunnison then via Durango and Ouray to Mesa Verde followed by Moab (Arches) and also Canyonlands.
From there they head back towards Denver via Colorado National Monument and Rocky Mountain National Park.
Note also that they tend to do a bit more hiking, and thus stay in each of the parks 2-3 nights, which fills in the remaining days.
Ouray is an Alpine resort and has hot springs, mountains on three sides. Check it out!
Michael is correct, it was an alternative route that would not include Idaho Falls so you would be changing the overnight destination.
Haha OK, i didn't realise to that - never mind, I found a way to make it all work that includes 2 nights in both Jackson and Gardiner (Yellowstone) :) There is a lot of small-town stops on this trip, so Idaho Falls, being a medium sized city, at least keeps my wife happy for somewhere to do a bit of shopping en-route! :)
Thanks for all the feedback - have discussed with my wife and I think we're reasonably settled on the below now :)
Day 1 - Arrive @ Denver, drive direct to Colorado Springs. Stay @ Colorado Springs
Day 2 - Colorado Springs + Pikes Peak.
Day 3 - Glenwood Springs (via US24 and CO-82)
Day 4 - Moab (via I70 & Colorado River Scenic Byway)
Day 5 - Moab + Arches National Park.
Day 6 - Moab + Dead Horse Point & Canyonlands
Day 7 - Vernal (via CO-139 and Dinosaur)
Day 8 - Jackson (via US191 and Rock Springs)
Day 9 - Jackson + Grand Tetons (Jenny Lake)
Day 10 - Idaho Falls (via US26)
Day 11 - Idaho Falls (chilling out and shopping)
Day 12 - Idaho Falls (chilling out and shopping)
Day 13 - Gardiner + Old Faithful/Grand Prismatic Spring (via US20)
Day 14 - Gardiner + Mammoth Springs/Grand Canyon of the Yellowstone
Day 15 - Thermopolis (via Beartooth Highway/Red Lodge/Cody)
Day 16 - Thermoplis + Hot Pools!
Day 17 - Estes Park (via Casper/Cheyenne, long day's driving, appx 7.5 hrs)
Day 18 - Estes Park (chilling)
Day 19 - Denver
Day 20 - Denver
Day 21 - Denver
Day 22 - Denver
Day 23 - Fly home.
I've got to tell you, I think you're still shortchanging Yellowstone with your current plans, and I don't think you're yet appreciating the size of Yellowstone, nor the slow nature of travel there.
While you're spending 4 full days in Denver and nearly 3 full days in Idaho Falls, you're still basically only spending a day and a half in Yellowstone - which strikes me as strange when you marked Yellowstone as a "must see" for this trip.
Idaho Falls to Gardiner, by itself is a 4 hour drive, so that only leaves you half a day to see the lower half of the park. I'm sure you'll enjoy it if that's all you can do, but it means there's a ton you won't have time to see.
I'll also say that Gardiner to Thermopolis via Beartooth and Cody could easily be an 8-10 hour day on the road. It's certainly longer than your "long day" of driving to Estes Park (not only is the distance longer, but the roads are much slower.
I'll stand by my previous recommendation that if Idaho Falls is a "must stop," then I'd go there directly from Moab, rather than going to Jackson, out to ID Falls, and doubling back to Yellowstone. That's adding quite a few miles to add in a mid-sized city.
I don't factor shopping into my planning, so perhaps there is something really special about the shopping in ID falls, but if it's just an average small/mid-size city with the chain stores you'd expect to find at most every regional shopping mall in the country, then I'd actually think Salt Lake City would be a better place to stop to "shop and chill." I'll also point out that Jackson itself is a resort town, much like Aspen and Estes Park, with lots of shopping options, albeit generally more high-end shopping than an average American mall.
If shopping in a good size town is needed, there’s plenty of shopping, including high end shopping, in Denver. Right now I’m thinking of Park Meadows that even has a Tesla dealer. https://www.parkmeadows.com/en.html
There are so many good places for shopping on your list already, and as just pointed out, Denver is one of the best ones. But I may be a little bit like Michael -- shopping never factors into my vacation planning.
I'm also not sure....why 3 days in Idaho Falls? Maybe I'm missing something, but to me, Idaho Falls is a place to stay when you go out to Craters of the Moon. That in itself could be done in a morning and then shopping in the afternoon...so two nights in Idaho Falls?
Back to the Yellowstone issue .... it takes one full day to see a lot on the "Lower Loop", which includes most of the geyser basins. It takes another full day to see a lot on the "Upper Loop", which is waterfalls, mountains, lakes, and hopefully some wildlife.
AAMOF, the wildlife are one of the major reasons why it's "slow going" in Yellowstone. You'll be going along from one scenic view to the next, and you'll come to a complete stop for a long time. Could be bear, moose, deer, bison, or even wolves. No one is going to let you around, it's that stopped up. Sometimes a ranger will come along and try to get traffic moving again.
Another slow going reason is parking. Now I believe you're going in the fall, so that might relieve some of the issues there. There's a huge amount of parking at Old Faithful, but there's also a ton of traffic there. You may end up parking a half mile across the parking lot, then have to hoof it up to the boardwalks there, THEN wait until Old Faithful is ready to go off. She is fairly regular -- thus her name -- but if you arrive after she's just gone off, you'll wait. BTW, there are some nice shops in the Old Faithful area. They are mostly gift shops. In other areas, you may pull into a scenic spot and have to wait for someone else to pull out. (We even had to wait at 7 in the morning at one such spot, in the summer.) My husband likens it to trying to shop at certain big-box stores in our area at Christmas....you drive around and around until you see somebody about to pull out!