Geography of Dallam County
Few places in Texas are as wide open as Dallam County. Only around 7,508 people live in its 1,505 square miles, and ranchland stretches for miles between settlements.
It lies in the West Texas region at about 36.28° N, 102.60° W and is one of the 25 largest counties in Texas (18th of 254). It is a border county, touching New Mexico and Oklahoma. Dallam County shares boundaries with 2 other Texas counties, and the closest major cities are Amarillo (about 85 miles away in a straight line) and Lubbock (about 191 miles).
West Texas is a land of long horizons: rolling plains, mesas and desert grassland where cotton farms, cattle ranches and the oilfields of the Permian Basin are the main sources of work. Distances between towns are measured in hours, not minutes.
For a broader view of how Dallam 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 7,508 residents across 1,505 square miles, Dallam County has a population density of about 5.0 people per square mile. Like much of West and South Texas, the county is sparsely populated, with wide-open country between settlements.
County seat: Dalhart
Dalhart is the county seat of Dallam County. This is where the county courthouse stands and where residents go for property records, vehicle registration, marriage licenses, court cases and voter services handled by the county clerk, district clerk and tax assessor-collector. In a county this sparsely settled, Dalhart may be one of only a few incorporated towns.
History & name origin
Dallam County was established in 1876 and was named for James Wilmer Dallam, a lawyer and newspaper publisher who had a close association with the Supreme Court of Texas. It was carved from territory previously part of Bexar County.
Dallam County, Texas — frequently asked questions
Quick answers about Dallam 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 Dallam County, Texas located?+
Dallam County is located in the West Texas region of Texas at approximately 36.278° N, 102.602° W. It is one of the 254 counties of Texas and carries U.S. Census FIPS code 48111. The interactive map on this page renders the official U.S. Census TIGER boundary for Dallam County over real-world OpenStreetMap, Esri satellite, and topographic basemaps.
How big is Dallam County in square miles?+
Dallam County covers approximately 1,505 square miles of land in the West Texas region — a large county by Texas standards. By land area it ranks 18th 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 Dallam County, Texas?+
Dallam County has a population of approximately 7,508 residents. With 1,505 square miles of land, that works out to a population density of about 5.0 people per square mile, which is sparsely populated for a Texas county. That makes Dallam County the 180th most populous of the 254 counties in Texas.
What is the county seat of Dallam County?+
Dalhart is the county seat of Dallam County, Texas, which was organized in 1876 and named for James Wilmer Dallam, a lawyer and newspaper publisher who had a close association with the Supreme Court of Texas. Dallam County was originally carved out of Bexar County. County government offices, courthouses, and most public records for Dallam County are located in Dalhart.
Which Texas counties border Dallam County?+
Dallam County shares borders with Hartley and Sherman counties. These 2 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 West Texas region.
Where can I download or print a map of Dallam County?+
Use the "Download PDF" button below the Dallam 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 Dallam 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 Dallam County, Texas?+
The full 5-digit U.S. Census FIPS code for Dallam County is 48111, made up of Texas state code 48 and the 3-digit county code 111. 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.