[4] The highway begins at a T-intersection with SR 13 at a point approximately two and a half miles (4.0 km) north of Fredericktown in Middlebury Township.

The majority of SR 546 passes through rural terrain, traveling amid vast farmland with a number of homes and the occasional patch of trees appearing alongside the highway.

The houses then spread out more as a wooded landscape takes shape as SR 546 approaches the point where Interstate 71 (I-71) goes over the state highway without a direct connection between the two.

The highway next bends to the northeast, and amidst the continued blend of woods and farmland with the occasional house, crosses the Kings Corners Road intersection.

As the highway turns to the north and then northeast, a series of dead-end side streets begin to appear, while still amid rural terrain.

Proceeding north from this intersection is Plymouth Street, which becomes county-maintained Lexington-Springmill Road once the roadway departs the village limits.