Its eastern terminus is at its junction with SR 73 approximately nine miles (14 km) west of Sinking Spring in the community of Belfast.

The highway turns east at Greenbriar Road, then bends to the northeast, and then more east-northeasterly as it emerges from the forest and into a landscape dominated by open farmland.

After passing the Young Road intersection, SR 785 goes amid a small patch of woods, then re-emerges into open farmland as it curves to the east.

Just after Locust Road, the highway bends to the northeast, nudging some patches of trees alongside the roadway to the southeast.

The highway enters into a residential area just prior to where it meets SR 73, which marks its endpoint.