Its watershed comprises 106 square miles (270 km2) within Shenandoah and Rockingham counties on the western slope of the Massanutten Mountain ridge.

[3] Smith Creek's major tributaries include: Smith Creek has been the beneficiary of a large-scale stream restoration project to revitalize the stream to a point where the native trout species can again thrive.

Prior to the Civil War, trout up to 5 and 6 pounds were common in the stream, but as forested land was converted to pasture land for livestock the stream became unsuitable for fish.

By 2006, populations have already been reestablished in Mountain Run, and they have begun migrating downstream.

[5] Fishermen continue to flock to the creek for its excellent fly fishing.