Mountain Branch is a long 1st order tributary to Aarons Creek in Halifax County, Virginia.
Mountain Branch rises in a pond about 3 miles northeast of Virgilina, Virginia, and then flows east to join Aarons Creek about 1.5 miles west of Nelson.
Mountain Branch drains of area, receives about 45.5 in/year of precipitation, has a wetness index of 354.52, and is about 40% forested.