Arizona has a plethora of historic, cultural and natural elements to consider as a possible heritage tourism destination. You will want to consider the time of year, the part of the state and your special interests as you consider Arizona for a possible visit. The biggest difficulty will be in cutting out places you want to go and see and 'saving them for the next time' rather than trying to find sites to visit.
My planning document may be of assistance, but it just scratches the surface, as well. Arizona has one National Heritage Area, Yuma Crossing, to assist in your planning, but it only covers one corner of your possible selections. There are also the Grand Canyon to the far north, Flagstaff and the I-40 corridor a bit south of that, the Mogollon Rim regions, numerous current and ancient Native American locations, and both the Phoenix and the Tucson areas, just to mention a few of the many geographical destinations possible.
Rich in Spanish as well as American history, Arizona has sites where Coronado explored, where Brigham Young sent Mormons, and where battles related to the Mexican War were fought as well as German, Italian and Japanese-American POW camps from the Word War II era. Arizona provides a wide variety of sites and activities from Spanish Missions to Spring Training Baseball to the Biosphere 2.
I had the opportunity to live in Arizona two times in my life, once sent as an Air Force Officer to a duty station and the second time by choice to escape the icy winters of Iowa. Two of my daughters received their undergraduate degrees at the University of Arizona and I earned my Ph.D. there. We have visited a number of times since. I could, have and will write and talk much about Arizona, but it is up to you, and your interests, of course, if you want to put it on your list for a future heritage tourism visit.