Yep, I agree with Michael and for all the same reasons as above.

You don't say how long you have in the Southwest and therefor is difficult to make meaningful suggestions but on the way between Santa Fe and Monument valley you could visit Taos Pueblo, Four corners, Mesa Verde NP and even Pagosa hot springs and take a famous train ride from Durango to Silverton. Further North in Southern Utah you have some great scenery and National parks such as Arches, Bryce canyon and Zion. If it is a return journey to Atlanta you could make a nice loop around the Southwest so have a look around the RTA site for ideas and if you have more questions come back with the relevant info and we can help to piece your trip together, have fun !