| State: | UT |
| Type: | SR |
| Route: | 66 |
| Map Custom: | yes |
| Section: | 112 |
| Length Mi: | 14.346 |
| Length Round: | 3 |
| Length Ref: | [1] |
| Established: | 1931 |
| Direction A: | South |
| Terminus A: | near East Canyon State Park |
| Direction B: | North |
| Terminus B: | in Morgan |
| Previous Type: | SR |
| Previous Route: | 65 |
| Next Type: | SR |
| Next Route: | 67 |
State Route 66 (SR-66) is a state highway in the U.S. state of Utah, connecting I-84 in the city of Morgan to SR-65 near East Canyon State Park over a distance of about 14.3miles.
The route's southern terminus is at its intersection with SR-65 near East Canyon State Park in Morgan County, where it winds to the west along the northern end of the park and East Canyon Reservoir. Heading away from the park, the route turns northwest as it travels through East Canyon, alongside East Canyon Creek.
As the canyon starts opens up and turn to the north, the route continues to follow, passing through Porterville and Richville. Eventually, as East Canyon merges with Weber Canyon, the route enters the city of Morgan] Here, the route intersects I-84, and immediately thereafter takes a right turn to the southeast, travelling approximately 3/4 mile as it parallels the north side of I-84, terminating at the next interchange.
State Route 66 was formed on 12 May 1931, connecting the town of Hardscrabble north to Porterville and Morgan. In 1953, the connection from Porterville to Hardscrabble was relinquished from state control. In 1969, the road from Porterville south to the East Canyon Reservoir was transferred from county to state control as a part of an SR-66 extension.[2]