In 1990, the state turned over the easternmost 16.8 miles (27.0 km) of SR 66 (known as Crookton Road) to Yavapai County for maintenance.

The terrain changes at a slower pace than the more direct Interstate 40, making it a scenic alternative at the cost of some time.

It still serves communities that the freeway avoids, including Valentine and Peach Springs; it enters the Hualapai Indian Reservation.

East of Seligman and continuing beyond Flagstaff, the area is mountainous (not desert) and covered with pine forests.

[4] In 1990, the state turned over the easternmost 16.8 miles (27.0 km) of SR 66 (known as Crookton Road) to Yavapai County for maintenance.