There are 5 US Post Offices in Erath County serving a total of 36,118 residents equating to 7,224 residents per post office. It's estimated that approximately 57,648 packages are handled across the 5 county post offices annually. Erath County (/\u02c8i\u02d0.r\u00e6\u03b8/ EE-rath) is a county located on the Edwards Plateau in the U.S. state of Texas. At the 2010 census, its population was 37,890. The county seat is Stephenville. The county is named for George Bernard Erath, an early surveyor and a soldier at the Battle of San Jacinto. Erath County is included in the Stephenville, Texas, Micropolitan Statistical Area. Erath County is the location of two of North America's largest renewable natural gas plants. The largest is at Huckabay Ridge, near Stephenville. The second largest is located outside of Dublin at Rio Leche Estates. On November 4, 2008, Erath County voters elected to allow the sale of beer and wine in the county for off-premises consumption."