Next time I'll pack my touring bike

60+ miles of this. Why take the bus if you're able to ride it. On my last summer road trip (Montana) I brought my trusty Trek 520. I brought my road bike to Alaska because my tourer needs a tuneup and I only could afford one service before I left. The road bike got tuned up so that's the one I packed. The Denali Park Road surface is compacted beyond Savage River, given the regular buses driving along it, so I know I could have ridden it as a roadie.
But I didn't have enough time or have the right gear for self supported solo riding to do it yesterday. No worries. The best bike is the one you have.