Two of us were on regular road bikes. We used a camelbak plus I jury-rigged a front pack on my handlebars to avoid excess weight/bulk on my back.

THe third girl brought a hybrid, it worked just fine. There were no instances where we had to make emergency stops, so no racking yourself on the bar required.

It really is beautiful, and Bozeman's not far. THat's where my friend lives who came to join us for the evening; she said it was about an hour and a half drive. Let me know next year if you want company! The roads also empty out in the fall, but I think it's a colder ride, and because we don't have deciduous trees except aspens, the colors aren't all that spectacular... I'd do someplace with colors!