Hi, and Welcome to the Great American Roadtrip Forum.

A rarely visited, and very interesting area is the Earthquake Lake Geological Area, on US-287, between US-87 and US-191. You can get brochures for a self guided auto tour of the area at the visitor centre in West Yellowstone, or the Area visitor centre on US-287 at the scene of the slide. The latter also has an old, but none the less interesting short movie of the event.

This was one of my most interesting discoveries on my trip last year, which is recorded at post 95 in this thread.

Lifey