Sand Branch is an unincorporated community in Dallas County, Texas, United States. A 2019 estimate put the population at around 100. Sand Branch is located approximately two miles south of U.S. Highway 175 and 14 miles southeast of Downtown Dallas on Belt Line Road in southeastern Dallas County. It is situated between the Trinity River and Hickory Cr…Sand Branch is an unincorporated community in Dallas County, Texas, United States. A 2019 estimate put the population at around 100. Sand Branch is located approximately two miles south of U.S. Highway 175 and 14 miles southeast of Downtown Dallas on Belt Line Road in southeastern Dallas County. It is situated between the Trinity River and Hickory Creek, southwest of Seagoville. Sand Branch is the only unincorporated settlement left in Dallas County, as the vast majority of the county lies within incorporated cities.