Both US 66 and US 89 split from I-40 again at Bill Williams Loop Road near McClelland Lake. The highway took the loop road for south of the Interstate before merging back into the route of I-40. At exit 161, US 66/US 89 curved northeast from I-40, then headed east on Historic Route 66 into downtown Williams. Parts of downtown Williams surrounding former US 66/US 89, including the roadway itself, are listed on the NRHP. The Williams Historic Business District and Urban Route 66, Williams, were added to the NRHP in 1984 and 1989, respectively. East of town, US 66/US 89 met the Santa Fe Railway at an underpass, then curved southeast onto an abandoned road, which tied into Mountain Man Trail in front of the Bearizona Wildlife Park. This was also the spot where US 66/US 89 intersected with the western terminus of SR 64, which headed north towards Valle and the Grand Canyon, while US 66 and US 89 continued east towards Flagstaff.