The best preserved section in the Southwest is in Arizona, between Topock on the Colorado river and Ash Fork east of Seligman - about 165 miles in total and including the main street of Kingman, the largest town on the route. Further east, another short stretch of original road runs through the centre of Williams, another historic old town.

Beyond Kingman, Route 66 crosses varied landscapes of sand, forest and scrubland for over 100 miles, through several small peaceful towns en route to I-40 near Ash Fork. Further east, the original route has largely disappeared under the interstate, but it reappears briefly to form the main street of Williams.

From Topock on the California border, the now little-used route crosses flat desert with many cacti, then across the Black Mountains via Sitgreaves Pass, close to many old mines and several ghost towns. There is a gradual descent past more desert scenery to Kingman, a historic railway town.