There are not that many main roads in that country. All are fine for RVs.
I travelled to the Navajo Res twice a year for a job for 6 years. Look carefully at all of the Native archaeological sites you can. Chaco Cy, Cyn de Chelley, Navajo Mtn and Navajo Nat Monument are not to be missed. A friend of mine got married at Keet Seal ruins which are about 10 miles off the road. Grandma came in on a donkey.
I used to take my field crews to the Holiday Inn near Kayenta with a view of Mon Valley. It is a tourist mecca. Our record for foreign languages heard during one happy hour was 7. Mostly we stayed at Tsegi Canyon and learned what it was like to be a minority. We knew we would be served last, but we learned to love the Dine and their culture.