US 66 followed the south frontage road for , then diagonally crossed I-40 onto a now-abandoned roadway through the Painted Desert, entering Apache County. Within Petrified Forest National Park, US 66 met at a junction with SR 63, which acted as the main route through the southern end of the park. Today, SR 63 is no longer a state highway and is known as Petrified Forest Road. US 66 continued northeast on the abandoned highway, which was located several miles north of I-40, through the heart of the Painted Desert. after the intersection with SR 63, US 66 arrived at the now-abandoned Painted Desert Trading Post. About northeast of the trading post, US 66 crossed over to the south side of I-40 onto County Route 7385. US 66 followed County Route 7385 around the Navajo Trading Post and McCarrell Memorial Cemetery to exit 330.