Largest counties in Texas

Look at a county map of Texas and the pattern is obvious: counties in the east are small and irregular, while counties in the west are huge rectangles. The reason is history and water. East Texas was settled first, by farmers who needed to reach a courthouse and return home in a single day by horse or wagon. The legislature drew counties small enough to make that possible — roughly 30 miles across — and followed rivers and old Spanish and Mexican land grants.

West of about the 100th meridian, rainfall drops below what row crops need without irrigation, and the land was used for open-range cattle ranching. Very few people lived there when the legislature divided the region in the 1870s and 1880s, so surveyors laid out large, straight-sided blocks. In the Trans-Pecos, where mountains and desert made settlement even sparser, counties became truly enormous.

The average Texas county covers about 1,031 square miles. The ten largest together cover 37,527 square miles — about 14% of the state — but are home to only around 379,819 people, or 1.2% of Texans.

Brewster County, with its seat at Alpine, covers 6,193 square miles — larger than Connecticut, and larger than Rhode Island and Delaware combined. Most of Big Bend National Park lies inside it, along with the Chisos Mountains, the only mountain range in the United States contained entirely within a national park. Its southern border is the Rio Grande, which forms the international boundary with Mexico.

Despite its size, the county has only about 9,458 residents. Alpine, home to Sul Ross State University, holds most of them; the rest live in small communities such as Marathon, Terlingua and Study Butte. Many residents drive more than 100 miles for specialized medical care.

• Ranching and energy economies. Cattle, sheep and goats have long dominated land use. Several of the largest counties — Pecos, Reeves and Culberson — sit on or near the Permian Basin, where oil and gas production has transformed local budgets.
• Public land and parks. Big Bend National Park, Big Bend Ranch State Park, Guadalupe Mountains National Park and the Davis Mountains bring visitors and conservation to the far west.
• Long distances for services. County governments in these places maintain hundreds of miles of road with small budgets, and sheriffs patrol territories the size of small states.
• Border geography. Many of the largest counties front the Rio Grande, giving them roles in international trade, ports of entry and border security.

Ranked by people rather than land, the largest Texas county is Harris with about 5,045,026 residents — more than many U.S. states. It is followed by Dallas, Tarrant, Bexar, Travis. None of these appears on the largest-by-area list; urban counties are generally mid-sized or small in land area. See our Texas county population guide for the full ranking.

If you plan to drive through far West Texas, fill up whenever you can — gas stations can be 60 miles or more apart, and mobile coverage is patchy in the mountains and along the river. Summer heat is extreme at lower elevations, while the Davis Mountains and Chisos Basin are much cooler. Check our interactive county map to see how these counties connect, and download a printable statewide map as a backup to your phone.