Utah State Route 123 (SR-123) is a state highway in the U.S. state of Utah. Spanning 11.4 miles (18.3 km), it connects the city of East Carbon with US-6 / US-191 in Carbon County.

Route description

State Route 123 begins at Sunnyside Junction on US-6/US-191, about 15 miles (24 km) southeast of Price. It heads east, passing through East Carbon-Sunnyside at the base of the Book Cliffs. It turns to the northeast and terminates shortly after it enters Whitmore Canyon.

History

The road from Sunnyside Junction through Sunnyside to Columbia (now all part of East Carbon-Sunnyside) was added to the state highway system in 1931, initially numbered SR-124 but changed to SR-123 in 1933. The route was shortened in 1935 by moving the eastern terminus back into Sunnyside, and splitting off the portion from Sunnyside to Columbia as SR-124.

Major intersections

The entire route is in Carbon County.

Location	mi	km	Destinations	Notes
Sunnyside Junction	0.000	0.000	US 6 / US 191 – Price, I-70	Western terminus
East Carbon	8.694	13.992	SR-124 – Horse Canyon
	11.421	18.380	"End State Maintenance" sign — Whitemore Canyon Road	Eastern terminus
1.000 mi = 1.609 km; 1.000 km = 0.621 mi