In 1946, the Arizona State Highway Department began planning a major improvement along US 66 between Flagstaff and Winslow. The plan was to construct a new highway between Flagstaff and Winona to shorten the travel time and the overall distance between Winslow and Flagstaff. The project was estimated to cost around $1,300,000 (equivalent to $ in ). Originally meant to be a single contract construction project, the bypass was later divided into two separate contracts. Bidding for both construction projects were opened on January 9 the same year with a scheduled completion date of September 30, 1947. The Fisher Construction Company and Tanner Construction Company were both awarded the contracts, with Fisher to construct the first east of Flagstaff and the remaining to be constructed by Tanner. By May 10, 1946, 30 percent of the section being constructed by Fisher was completed.