Dry Run (Birds Branch tributary)Dry Run is a long 1st order tributary to Birds Branch in Patrick County, Virginia.CourseDry Run rises about 2 miles southwest of Groundhog Mountain in Patrick County, Virginia and then flows south-southeast to join Birds Branch about 1 mile west-northwest Ararat.WatershedDry Run drains of area, receives about 50.8 in/year of precipitation, has a wetness index of 378.73, and is about 45% forested.