I cannot help much but I've just returned from a week in Yellowstone (rental car). An AMAZING place. "Bison blocks" are common where drivers of everything from small cars to class A motor homes loose their minds and create huge traffic jams. Be very careful cycling through those. Drivers have gone mad!!!

We did see touring cyclists enjoying the park ( best at dawn and at dusk) and I envied them. But when I saw them grinding up the long steep grades I was amazed and not envious. I could not do that. Good luck. Take the real long walks thru the various geothermal basins etc. I'd never been so in touch with our planet's internals before. Awesome.