Route 146 started in Pleasant Grove at the intersection of 100 East and State Street US-89.

Travelling north on 100 East, the route left Pleasant Grove, turned into Canyon Road, and traveled along the eastern foothills of Cedar Hills, Utah until it ended at the Alpine Loop Scenic Byway at the mouth of American Fork Canyon.

[3] SR-92 (then numbered SR-80) was established in 1935 and had its eastern terminus at SR-74,[4] but in 1941 was extended east to the Uinta National Forest boundary in American Fork Canyon,[5] replacing the 1.7-mile (2.7 km) stretch of SR-146 between SR-74 and the mouth of the canyon.

[6] SR-146 remained unchanged until 2014, when it was decommissioned in a jurisdictional transfer with Utah County.

The transfer was approved by the Utah Transportation Commission on December 5, 2014.