From 1967 to 2013, the district included large portions of Dallas County. Eventually, the 3rd covered much of northern Dallas County, including Garland, Rowlett and much of northern Dallas itself. It was pushed into Collin County in 1983. Since then, Collin County's rapid growth resulted in the district's share of Dallas County being gradually reduced. After redistricting in 2012, the Dallas County portion of the district was removed altogether. However, it still includes the Dallas precincts located in Collin County.
