About: 1977 Utah state route renumbering

In 1977, the Utah State Legislature changed its system of how state route numbers were used and assigned. Prior to 1977 Utah used a system where every U.S. Highway and Interstate Highway traversing the state was assigned a different Utah state route number. This state route number was not posted on signs, but was only used for legislative purposes, such as funding. There were many instances where having different route numbers for signing and legislative purposes could cause confusion. For example, the highway signed Interstate 15 in Utah was legislatively defined State Route 1, not route 15. State Route 15 also existed, but was a different route that passed through Zion National Park.