This place is AMAZING. Take your time and fully explore each stop along the tour. There's so much history and so many things to see. The old theater had such an incredible (and somber) feeling to it, and reading about things like the riot was really cool. It's really inexpensive and totally worth spending the time. I can't recommend this place enough. Gift shop was great, car museum was cool, and I left there feeling like I had just experienced history firsthand. Don't skip this stop- you'll regret it!
We stayed in Butte on the way to CDA. The Pit was really cool and educational. It's not something you see every day. Butte is a fascinating town.
It's a rough and bumpy ride to get there, but it's pretty cool to see. Just make sure you do some research on whether you'll be able to see it at the time you're going. The water level can be too high and you'll miss it completely. While you're at it, spend some time at the golden spike museum.