Geography of McMullen County
McMullen County sits at roughly 28.35° N and 98.57° W in the South Texas region of Texas, spanning 1,113 square miles of terrain that includes the landscape characteristic of the area — from open ranchland and farmland to small-town main streets. The county's centroid is near Tilden, and the county shares boundaries with 4 neighboring counties.
Population & demographics
With approximately 544 residents across 1,113 square miles, McMullen County has a population density of about 0.5 people per square mile. Like much of West and South Texas, the county is sparsely populated, with wide-open country between settlements.
County seat: Tilden
Tilden serves as the seat of government for McMullen County. The county courthouse, commissioners court, district clerk, and primary public records are located here. As with all 254 Texas counties, the county seat is the anchor of civic life and the principal address for elections, permits, and court filings.
History & name origin
McMullen County was established in 1858 and was named for John McMullen (1832–1883), an Irish-born empresario in Texas. It was carved from territory previously part of Atascosa County, Bexar County and Live Oak County.
McMullen County, Texas — frequently asked questions
Quick answers about McMullen County geography, population, county seat, neighboring counties, and how to use the maps on this page. Every answer is generated from the official U.S. Census data backing this site.
Where is McMullen County, Texas located?+
McMullen County is located in the South Texas region of Texas at approximately 28.353° N, 98.568° W. It is one of the 254 counties of Texas and carries U.S. Census FIPS code 48311. The interactive map on this page renders the official U.S. Census TIGER boundary for McMullen County over real-world OpenStreetMap, Esri satellite, and topographic basemaps.
How big is McMullen County in square miles?+
McMullen County covers approximately 1,113 square miles of land in the South Texas region — a mid-sized Texas county. By land area it ranks 48th out of 254 Texas counties. The full bounding box of the county is rendered to scale on the interactive map and matches the U.S. Census TIGER 2023 polygon.
What is the population of McMullen County, Texas?+
McMullen County has a population of approximately 544 residents. With 1,113 square miles of land, that works out to a population density of about 0.5 people per square mile, which is sparsely populated for a Texas county. That makes McMullen County the 251st most populous of the 254 counties in Texas.
What is the county seat of McMullen County?+
Tilden is the county seat of McMullen County, Texas, which was organized in 1858 and named for John McMullen (1832–1883), an Irish-born empresario in Texas. McMullen County was originally carved out of Atascosa County, Bexar County and Live Oak County. County government offices, courthouses, and most public records for McMullen County are located in Tilden.
Which Texas counties border McMullen County?+
McMullen County shares borders with La Salle, Live Oak, Atascosa, and Duval counties. These 4 neighboring counties are highlighted on the schematic boundary map and linked at the bottom of this page so you can quickly compare population, area, and county seats across the South Texas region.
Where can I download or print a map of McMullen County?+
A free, print-ready PDF map of McMullen County is available from the "Download PDF" button at the top of this page. The printable layout uses authentic U.S. Census TIGER boundary geometry for McMullen County, includes a Texas locator inset, and is sized for standard 8.5" × 11" Letter paper. For interactive use, the live Leaflet map on this page supports OpenStreetMap, Esri satellite, Esri topographic, and Carto light basemaps with zoom, scale bar, and fullscreen.
What is the FIPS code for McMullen County, Texas?+
The full 5-digit U.S. Census FIPS code for McMullen County is 48311, made up of Texas state code 48 and the 3-digit county code 311. This is the same FIPS code used by the U.S. Census Bureau TIGER/Line files, the American Community Survey, and most federal datasets that key on county.