I've visited the Badlands more times than any other park (aside from our nearby Rocky Mountain National Park), and each time I'm amazed by the colors and shapes of the rock formations there. At 244,000 acres, the Badlands includes a lot of varied terrain. 69 million years ago, the area was covered in a massive sea, and sediments that sunk to the bottom created these colorful layers (and also made a great spot for fossils)--then erosion carved out the different formations.
Badlands is the sort of park that you can just drive through--with a couple photo stops here and there--and still get a great experience. In fact, the road is so winding that it manages to pass by nearly all of the best parts (though nothing can ever really compare to hiking and camping in the backcountry).
The last time I went was with Andy, and we decided to stay overnight mostly because camping was free (and we had a National Parks Pass so admission was free, too!). We were passing through after a long day of driving (with another one ahead), so backcountry felt like a bigger endeavor than we were up for. Instead we drove down a ridiculously long gravel road, past endless stretches of grass speckled with bison, to arrive here:
One of Andy's favorite stories comes from the next morning, when I was driving us back down that long gravel road to the main park. There were bison everywhere, and warning signs like this:
And I thought out loud, "Man, my worst nightmare right now would be coming across a stupid bison right in the middle of the road!" So of course, we rounded a corner and BAM! There was a gigantic (and not particularly smart looking) bison right in the middle of the gravel road. We were in my dinky 2-door car, and I didn't know what to do. Andy suggested revving the engine (with me all "No! We'll make him mad!"), which caused the bison to turn towards us, dip his head down, and paw the ground with a front hoof.
I had kind of been joking about the nightmare thing originally, but now there was an angry buffalo putting a macho show on in front of us and I was freaking out. Which Andy thought was hilarious. But he agreed to switch so he could drive (I think I crawled into the passenger seat while he walked around the car). And then an SUV came up on the bison's other side and he moseyed nonchalantly back to his herd. Crisis averted, I say.
For me I would say that the Badlands makes a great 1-2 day experience, but to make it part of a bigger trip rather than a destination. Though pretty far from Yellowstone (pushing 9 hours on mostly 75 mph roads), the Badlands is only 1-1.5 hours east of Keystone (with Mount Rushmore, Crazy Horse, and a bunch of toursity things) plus Wind Cave National Park and Custer State Park a little ways past that. That same area also includes Jewel Cave and Devils Tower National Monuments, though I haven't been to either of those. And around 3 hours west of the Badlands is the Mitchell Corn Palace (the world's only corn palace, if you can believe it). Yeah buddy.
Here are a couple more shots for the road...