US 66 met US 93 and US 466 at a former highway junction, which is now the spot of Locomotive Park, the home of Santa Fe Railway No. 3759, a 3751 class 4-8-4 Northern steam locomotive. US 66 continued through town on Main Street, and curved northeast towards I-40 at the eastern end of Kingman. About northeast of Kingman, US 66 crossed under present-day I-40, and continued northeast through the present day Kingman metro area on what is now SR 66. Kingman to Seligman Between Kingman and Seligman, I-40's more southerly and more direct path diverges from former US 66 by approximately , putting considerable distance between former US 66 and the current Interstate. SR 66 and Crookton Road comprise the route of old US 66 between Kingman and Seligman. The state highway designation currently covers just of a section east of Kingman. As US 66 headed northeast from Kingman on SR 66 and paralleled the Santa Fe Railway, the highway made a gradual northeastern curve about from Kingman, and entered another mountain range, where it arrived at the town of Hackberry. From Hackberry, US 66 then curved northeast through the mountains, passing through the towns of Valentine and Crozier. Upon entering a small mountain valley, the highway passed through the town of Truxton before entering the mountains again at Peach Springs. Between Valentine and Peach Springs, SR 66 takes a later routing of US 66, which is straighter and has fewer curves. The older, less straight alignment, used through 1940, can be seen on either side of present-day SR 66. A natural feature and tourist attraction called the Grand Canyon Caverns, just east of Peach Springs, are among the largest dry caverns in the United States. Upon leaving Peach Springs, US 66 curved southeast into the Hualapai Indian Reservation. Shortly afterwards, the highway left Mohave County and continued east into Coconino County. Shortly after entering Coconino County, US 66 entered Yavapai County. The route briefly entered Coconino County again for less than , before crossing into Yavapai County for a second time, where it remained for several miles. This final crossing of the Yavapai–Coconino county line also serves as the present terminus of SR 66. From here on out, US 66 continued southeast as a county-maintained road (known as Crookton Road). This segment was previously the easternmost of SR 66, until ADOT retired this section and handed it over