Before it was settled in the nineteenth century, the future LaSalle County was an area of grasslands punctuated by clumps of mesquite, oak, and ash trees. The abundant wildlife included deer, turkeys, wild horses, and mountain lions. Springs rising from a reservoir of underground water fed streams, lakes, and water holes that harbored beavers, alligators, big fish, crawfish, and mussels. Artifacts dating from the Paleo-Indian period (9200 to 6000 B.C.) demonstrate that human beings have lived in the area for about 11,000 years. The Indian population seems to have increased during the Archaic period (6000 B.C. to A.D. 1000), when many groups of hunter-gatherers spent part or all of their time in the area. During this period the inhabitants subsisted mostly on game, wild fruits, seeds, and roots. They carved tools from wood and stone and wove baskets and rabbit-skin clothing. The hunting and gathering way of life persisted into the Late Prehistoric period (A.D. 1000 to the arrival of the Spanish), though during this time Indians in the areas learned to make pottery and hunted with bows and arrows. During the eighteenth century the Coahuiltecan Indians were squeezed out by Apaches, raiding Comanches and other groups who were migrating into the area, and by the Spanish, who were moving up from the south.

No permanent Spanish settlements seem to have been established in what is now LaSalle County. Beginning in the late 1600’s, however, Spaniards passed through on the Old Presidio Road (Camino Real) through the eastern part of the Covert Ranch to and from other Spanish settlements in Texas including San Antonio, which was founded in 1718. After Mexican independence in 1821 from Spain, the Mexican government used land grants to encourage its citizens to settle in Texas. In 1834, for example, Jesus Cardenas received 31,500 acres of land along the Nueces River, including about 10,000 acres in what is now LaSalle County, and a large part of the county was included in a tract granted to John McMullen, an Irish impresario. Few if any grantees seem to have actually settled on their lands, however. In 1836 the area remained populated almost entirely by Indians.

Between the Texas Revolution or War of Texas Independence from Mexico (1835-1836) and the Republic of Texas (1836-1845), most of what is now LaSalle County lay in the disputed area between the Rio Grande to the south and the Nueces River to the north, known as the Nueces Strip. Since neither the Republic of Texas nor the Mexican government could establish control over this strip of land, it became a haven for desperados. The Treaty of Guadalupe Hidalgo in 1848 between The United States and Mexico established the current international boundary at the Rio Grande river and United States sovereignty forever over the Nueces Strip. However, later, Mexico allied with Germany in World War I in hopes it would regain some of its former territory. In World War II Mexican President Camacho declared war on Germany, finally giving up the former strategy. Outlaws and hostile Indians delayed the development of the Nueces Strip area for years. When LaSalle County was officially divided from the Bexar District on February 1, 1858, the county had only begun to be settled.

In 1880 the county was organized into a district political unit at the Old Guajuco Ranch and was named after Rene Robert Cavelier, Sieur de la Salle, a French explorer who followed the Mississippi from its headwaters to the Gulf of Mexico, during the period from 1678 through 1682.

LaSalle organized another expedition to explore the Mississippi in 1684. He missed the Mississippi and landed in the Matagorda Bay area in February, 1685. LaSalle established Fort St. Louis and made several expeditions into Texas during the next two years before he was murdered by his own men.

Although LaSalle failed to establish a permanent French presence in Texas, he did give France claim and stimulated French interest in the Mississippi. That in turn stimulated Spanish efforts in Texas and led to the establishment of missions in East Texas in 1690, greatly accelerating European settlement of the state.

Again, LaSalle County was formally organized in 1880. The last Indian raid in the county occurred in 1878, 8 years after the end of the civil war. In the early 1880s the International Great Northern Railroad extended its tracks into the county. These developments, along with the gradual elimination of outlaws, helped to make ranching a more predictable and profitable enterprise.

Cattle ranches firmly established themselves in the county during the late nineteenth century, especially after the 1880s, when barbed wire fencing was introduced. At the turn of the century ranching completely dominated LaSalle County’s economy, and set the tone for its culture.

The settlement and development and vegetable farming boom of the 1920s died with the onset of the Great Depression. After World War II cattle ranching continued to be the primary economic activity in the county. Meanwhile, oil and gas production had become an important source of revenue.

The rangeland in LaSalle County serves the dual function of livestock production and habitat for various kinds of wildlife. The basic habitat requirements for any wildlife population are food, cover and water, each one abundant on the ranch. Much research has been done on the food habits and nutritional requirements of the white tailed deer. The native rangelands of South Texas provide excellent habitat for meeting the dietary needs of a deer population. Deer require a diet of approximately 16 percent protein plus various minerals and energy to be well nourished. Deer are selective foragers, preferring to feed on a wide variety of plants rather than a few specific ones. The leaves, twigs and fruit of woody brush species, along with weeds and forbs, make up the bulk of their diet. Small amounts of grass may be taken seasonally.