The A. M. "Mac" Stringfellow Unit is a Texas Department of Criminal Justice prison located in unincorporated Brazoria County, Texas, with a Rosharon, Texas postal address it is not inside the Rosharon census-designated place. The prison is located on Farm to Market Road 655, 4 miles (6.4 km) west of Farm to Market Road 521, and about 30 miles (48 km) south of Houston. The unit is co-located with the Ramsey Unit and the Terrell Unit on a 16,369-acre (6,624 ha) plot of land.