SR-28 begins at an intersection with US-89 in central Gunnison and heads north and northwest to Fayette.

The portion of SR-28 between US-89 and the I-15 interchange south of Nephi (Exit 222) is part of the National Highway System.

However, perhaps in preparation for the eventual replacement of US-91, which was being quickly superseded by the new Interstate 15, in 1968, the legislature redesignated several portions of US-91 with new numbers: SR-163 (renumbered SR-78 in the 1977 renumbering) from the point where US 91 diverged from I-15 at a proposed interchange west of Levan eastward to that town, an extension of SR-28 from Levan northward along old US 91 to a proposed interchange with I-15 two miles (3.2 km) south of Sheep Lane, and State Route 41 from another interchange one-half mile (0.8 km) south of Sheep Lane through Nephi to the north end of the bypass.

These changes left a section of old US 91 between the two interchanges approximately 1.5 miles (2.4 km) in length which would become a local road.

[5] Media related to Utah State Route 28 at Wikimedia Commons