Geography of Mason County
Mason County is classic frontier Texas: 932 square miles of open land with only about 3,990 residents, which makes it one of the most thinly settled counties in the state (203rd of 254 by density).
It lies in the Central Texas region at about 30.72° N, 99.23° W and is 97th in size among Texas's 254 counties. Mason County shares boundaries with 6 other Texas counties, and the closest major cities are San Angelo (about 88 miles away in a straight line) and Austin (about 94 miles).
Central Texas stretches across the Hill Country, the Blackland Prairie and the Cross Timbers. It includes some of the fastest-growing suburbs in the nation along the I-35 corridor, alongside quiet ranching counties with limestone creeks and live-oak savanna.
For a broader view of how Mason County fits within the state, download our free Texas map with counties and cities PDF — a printable, high-resolution reference showing all 254 Texas counties labeled with their county seats.
Population & demographics
With approximately 3,990 residents across 932 square miles, Mason County has a population density of about 4.3 people per square mile. Like much of West and South Texas, the county is sparsely populated, with wide-open country between settlements.
County seat: Mason
County government for Mason County is based in Mason — one of several Texas county seats that carry the same name as their county. The commissioners court, made up of a county judge and four precinct commissioners, meets here and sets the county budget, roads policy and tax rate. In a county this sparsely settled, Mason may be one of only a few incorporated towns.
History & name origin
Mason County was established in 1858 and was named for Fort Mason, which was named for either Lt. George T. Mason, killed during the Mexican–American War in fighting near Brownsville, or for Gen. Richard Barnes Mason, military governor of California. It was carved from territory previously part of Gillespie County.
Mason County, Texas — frequently asked questions
Quick answers about Mason County geography, population, county seat, neighboring counties, and how to use the maps on this page. Figures are sourced from the U.S. Census Bureau; answers are written and reviewed by the Texas County Map team.
Where is Mason County, Texas located?+
Mason County is located in the Central Texas region of Texas at approximately 30.718° N, 99.226° W. It is one of the 254 counties of Texas and carries U.S. Census FIPS code 48319. The interactive map on this page renders the official U.S. Census TIGER boundary for Mason County over real-world OpenStreetMap, Esri satellite, and topographic basemaps.
How big is Mason County in square miles?+
Mason County covers approximately 932 square miles of land in the Central Texas region — a mid-sized Texas county. By land area it ranks 97th 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 Mason County, Texas?+
Mason County has a population of approximately 3,990 residents. With 932 square miles of land, that works out to a population density of about 4.3 people per square mile, which is sparsely populated for a Texas county. That makes Mason County the 208th most populous of the 254 counties in Texas.
What is the county seat of Mason County?+
Mason is the county seat of Mason County, Texas, which was organized in 1858 and named for Fort Mason, which was named for either Lt. George T. Mason, killed during the Mexican–American War in fighting near Brownsville, or for Gen. Richard Barnes Mason, military governor of California. Mason County was originally carved out of Gillespie County. County government offices, courthouses, and most public records for Mason County are located in Mason.
Which Texas counties border Mason County?+
Mason County shares borders with Menard, San Saba, McCulloch, Kimble, Llano, and Gillespie counties. These 6 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 Central Texas region.
Where can I download or print a map of Mason County?+
Use the "Download PDF" button below the Mason County map on this page to save a letter-size PDF of the county boundary, neighboring counties and incorporated places, drawn from U.S. Census Bureau 2023 boundary files. The "Official TxDOT road map" button downloads the Texas Department of Transportation county road mapbook for Mason County. Both files are stored on this site and download directly. Our free Texas map with counties and cities PDF shows all 254 counties on one sheet.
What is the FIPS code for Mason County, Texas?+
The full 5-digit U.S. Census FIPS code for Mason County is 48319, made up of Texas state code 48 and the 3-digit county code 319. 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.