Dimmit County Texas map

The county lies in the southwestern corner of the South Texas brush country, between the Rio Grande at Eagle Pass and the Nueces. Five counties border it: Zavala to the north, Frio northeast, La Salle east, Webb south and Maverick west.

Eagle Pass and its international bridges are 49 miles northwest in a straight line, Laredo 64 miles southeast, Del Rio 94 miles northwest and San Antonio 103 miles northeast. Dimmit does not touch Mexico itself, but it sits between two of the busiest crossings on the Texas border and carries their truck traffic.

The Nueces River forms the eastern and southern boundary with La Salle and Webb counties. This far down its course, and this far west, the Nueces is often a wide sand bed with water standing only in pools between rains. Six of the county's 1,335 square miles are water.

Dimmit County was laid out in 1858 from parts of Bexar, Maverick, Uvalde and Webb counties, but it was too thinly settled to organise a government until 1880. It is named for Philip Dimmitt, a commander at Goliad during the Texas Revolution; the county's name lost a "t" through an error in the bill that created it, and the misspelling stuck.

Three incorporated towns, all founded on irrigation and the railroad in the first two decades of the 20th century, hold about three quarters of the county's 8,615 people. Asherton and Big Wells were both promoted as irrigated colony towns and both are smaller now than they were. Catarina, in the south of the county on US-83, is unincorporated but appears on every map: it was another irrigation colony, and it became a base for drilling crews during the shale boom.

The Carrizo Sand aquifer outcrops across this part of South Texas, and in places its water was once under enough pressure to flow from a well without pumping. From about 1900, land companies drilled artesian wells, cut the brush, laid out towns and sold irrigated tracts to buyers from the Midwest on the promise of vegetables grown in winter while the north was frozen. That is the origin of the name Winter Garden, applied to Dimmit, Zavala and neighbouring counties.

Spinach, onions, cabbage, carrots and beets were the crops, shipped out by rail. The district never quite matched the promotional literature — water pressure fell, freezes came, and the acreage contracted through the 20th century — but irrigated vegetable and row-crop farming remains part of the county, alongside the pecan orchards and the cattle and hunting land that took back most of the cleared brush.

The Eagle Ford shale runs diagonally across South Texas, and its western end is gas and condensate rather than crude. Dimmit County lies squarely in that window, and from about 2009 it was one of the most heavily drilled counties in the play. Rig counts, truck traffic and rental housing all spiked, county sales tax collections rose sharply, and Carrizo Springs and Catarina gained work camps and pipe yards, then lost most of them again when gas prices fell.

What is left on the map is the infrastructure: gathering lines, compressor stations, caliche well pads visible from the FM roads, and a road network that was rebuilt in places to take the loads. Between the wells, the Chaparral Wildlife Management Area — state land on the eastern side of the county, shared with La Salle — keeps a large block of South Texas brush in something like its original condition, and is used for deer and quail research and for public hunts.