Lots to see between GC and Yellowstone. Zion, Bryce, Arches, just to name a few places. Hope your able to see some of those also, and just take the time to enjoy the wide open spaces out west.
Even never leaving your vehicle you will see wonderful amazing sights.
Planning is half the fun, lots to see between NY and the West, depending on the time you have and what other areas you have visited before. Enjoy
2011 Toyota Tundra double cab