American Association of State Highway and Transportation Officials, Route Numbering Committee Agenda (1985)
“ UTAH Extension of U.S. Route 666 DISAPPROVED Beginning at the present the terminus of U.S. Route 666 at Monticello, then southerly over U.S. Route 191 to the intersection of State Road 95, then northwesterly over SR 95 to the intersection of SR 24, then northwesterly over SR 24 to the intersection of SR 119, then westerly over SR 119 to the intersection of SR 120, the westerly SR 120 to the intersection of I-70 southwest of Richfield. ”
