The entirety of the highway is routed along Main Street.

The route proceeds north along a two-lane undivided highway from the intersection of Center Street (SR-143) and Main Street in the middle of Parowan in Iron County.

[2] With the construction of I-15 around Parowan imminent, SR-1 was moved from old US-91 to the proposed bypass in 1968.

[3] However, plans had changed by the time I-15 was completed in 1975, and a second interchange (exit 75) served the west side of Parowan.

SR-143 was instead rerouted south and west to meet I-15 there, and what had become part of SR-143 in 1968 was instead redesignated SR-274.