Cattle theft by Indians was a common hazard of early settlers in Texas. Though the Indians more often stole horses, when their food supply was short, they drove off and butchered beeves, dairy cows, and oxen. Sometimes they stole beyond their needs to avenge wrongs or to drive white settlers from their hunting grounds. Occasionally they started stampedes and killed cattle they could not drive off. In the Civil War and Reconstruction periods, Mexican rustlers gave much trouble along the border. In claims made against the Mexican government, it was asserted that from 1859 through 1872 Mexican bandits stole 145,298 cattle from various South Texas ranches. The depredations of Indian and Mexican rustlers, however, fell far short of those perpetrated by white renegades. In fact, ranchmen in Mexico often were victimized by Texas thieves who swam large herds of "wet stock" across the Rio Grande by night and trailed them to Kansas markets. Other rustlers stampeded herds on the northward trails and drove off as many cattle as they could, using six-shooters to defend themselves if pursued. Many preyed on herds that grazed on the western ranges, especially where canyons or high brush afforded hiding places.
Most rustlers of the open-range era were cowboys who had drifted into dubious practices. They knew the cattle country and were adept at roping, branding, and trailing. One needed only to buy a few cows, register a brand, and begin branding strays. Many cowboys' herds increased so rapidly that some ranchmen refused to hire any hand who had stock of his own. The altering of brands was a frequent practice among rustlers. Instead of the stamp iron used by most cattlemen, the rustler used a running iron—a straight rod with a curve at the heated end. When this was outlawed, he sometimes used a piece of heavy wire that he could bend into any shape and carry in his pocket.
More common was the theft of large unbranded calves. When a ranchman neglected to brand some of his calves before they were weaned, it was easy for the rustler to cut a pasture fence, drive the calves to his corral, and stamp his own brand upon them. Often he was not content with this but would return to take also the smaller calves, not yet weaned. This was more ticklish procedure, since Longhorn cows and calves had a strong instinct for returning to each other, even when separated by miles. Such reunions had to be prevented, for if a ranchman found a calf with a rustler's brand nursing from one of his cows, there likely would be trouble. Before branding unweaned calves, often the rustler kept them penned until they quit bawling and learned to eat grass. Other measures used to keep them from getting back to their mothers and to hasten weaning were to cut the muscles supporting the calf's eyelids and thus make it temporarily blind, to apply a hot iron between the toes to make the calf's feet too sore for walking, or, in uncommon cases, to split the calf's tongue to prevent suckling. The rustler might also kill the mother to make the calf a genuine orphan.
With county seats far apart, grand juries disinclined to indict, and trial juries reluctant to convict, early cattlemen often had to take law enforcement into their own hands in dealing with rustlers. Following the transition from the open range to fenced ranches, rustling gradually was lessened by efforts of local officers, the Texas Rangers, and inspectors of cattlemen's associations, who checked brands as cattle were sold at livestock markets. Rustling was not entirely stamped out, however, and in the 1930s it broke out in a new form. Thieves equipped with fast trucks stole cattle at night, butchered them in nearby thickets, and sold the meat the next day in markets perhaps several hundred miles away. The extent of this rustling and the fact that the thieves often crossed state lines led Congress in 1941 to pass the McCarran Act, which provided a maximum penalty of a $5,000 fine and five years in prison for transporting across state lines stolen cattle or meat from such cattle. This measure, however, did not prevent the sale of stolen meat in black markets during World War II.
In the late 1970s, a new type of thief emerged known as the "Suburban rustler." This individual usually attacked unattended ranchettes, stole four or five head, and took the cattle immediately to auction. Techniques of theft in the later twentieth century included anesthetizing cattle with hypodermic darts, using trained bulldogs to bring the animals down, and herding the booty with helicopters. As the price of beef escalated, so did the ingenuity of the rustlers. Since the early twentieth century, the Texas and Southwestern Cattle Raisers Association has employed field inspectors to police cattle rustling. These agents, deputized by the Texas Department of Public Safety as Special Texas Rangers, helped to recover 4,000 cattle in 1993.