I loved Yellowstone, almost went back to work there but then met my hub!
A couple tips:
Come in Northeast Entrance to see the most Grizzly and Wolfs, so cool out that way too before you get to the park.
Head over to Mammoth for the best pool viewings and check out Gardner, really cool old timey town with a great local pizza joint and good rafting outfitters.
If you are down for some neat shops visit West Yellowstone, they had some neat vintage and western stores.
And if you dig the massive bison herds and elk take the trip from Canyon down to Fishing Bridge. That's the best area to get caught up in Bison and Fishing Bridge is cool in July, you can watch the fish run.
Then I'd leave out the East entrance and visit Cody.
Can't wait till I get back there!
I used to do a lot of wilderness riding up there, but Mrs. Face is not into being quite that primitive and gets a bit spooked by the remote isolation. So I opted for dude ranches with her - a bit more civilized. Our favorite dude ranch, which we have been to several times is not far out of the east side of Yellowstone. It's right on the Shoshone, with very scenic riding in beautiful country. That particular dude ranch devotes a day to Yellowstone, incorporates a raft ride down the Shoshone, and some time in Cody for a rodeo and the Buffalo Bill Historical Center, which you no doubt have been to if you have been to Cody. All in all, a beautiful area, and lots of varied activities. I have always driven there, but the way it is set up you don't really need a car.
To the OP, another great vacation spot is Colorado Springs. I can't begin to tell you how much there is to do within an hour drive of CS. We try to make it there at least every other year. Our favorite time there of course is about the last week of September when the Aspens are out. Bear with a couple of pictures...
Mrs. Face up around tghe Cripple Creek area...
Mrs. Face and sister of Face near the top of Phantom Canyon...
Mrs. Face and sister of Face in Garden of the Gods in Colorado Springs...
Taken from the Garden of the Gods visitor center...
Of course my plugging Colorado Springs doesn't have anything to do with the fact that Mrs. Face's niece and her husband just finished designing the new Colorado Springs logo just released last week... New Colorado Springs logo unveiled | colorado, springs, logo - Colorado Springs Gazette, CO