The southern terminus of SR 300 is at a T-intersection with U.S. Route 6 (US 6) approximately 1.50 miles (2.41 km) west of the village of Helena.

SR 300 passes through a primarily residential portion of Gibsonburg as it crosses the CSX railway line, with side streets meeting the highway along the way.

The highway passes a few commercial businesses on the outskirts of the village, and upon crossing CR 79, the route re-enters rural Madison Township, bounded by a large pond and trees to the west and some homes to the east.

Upon crossing into the township, the route travels amidst a primarily forested terrain as it passes its intersection with CR 115, and then arrives at its endpoint at the four-lane divided US 20 southeast of Woodville.

[4] Frequently, the Ohio Department of Transportation (ODOT) conducts surveys throughout its highway system to determine the volume of traffic utilizing it.

According to a 2009 survey, ODOT determined that the portion of SR 300 with the highest traffic volume was the stretch between CR 65 south of the Gibsonburg village limits and SR 600 in downtown Gibsonburg, which saw an average of 2,740 passenger vehicles and 90 commercial vehicles on a daily basis.