The history of livestock grazing in the Jornada Basin of southern New Mexico is a relatively recent story, but one of profound implications. For four centuries this region has supported a rangeland livestock industry— initially sheep (Ovis aries), goats (Capra aegagrus hircus), and cattle (Bos taurus and Bos indicus), but primarily beef cattle for the past 130 years. Throughout this brief history of a domesticated ruminant in an ecosystem without a significant presence of large hoofed mammals as part of its evolutionary development, the livestock industry has continually grappled with high degrees of temporal and spatial variation in forage production. Management of this consumptive use, whether during Spanish, Mexican, U.S. territorial, U.S. federal, or New Mexican governments, has constantly reaffirmed the need for grazing management to be flexible and responsive to the stress of droughts. The history of anecdotal experiences has been more recently augmented by scientific investigations first initiated in 1915. This chapter outlines the general history of livestock in this region, defining characteristics of herbivory in arid lands, and principles of grazing management derived from nearly a century of studies on grazing by large domesticated herbivores. Seventeen ships carried 1,200 people and enough cattle, horses, sheep, and pigs to colonize northern Hispaniola during Columbus’s second voyage in 1493. Livestock originating from the Andalusian Plain of southern Spain were loaded aboard ship at the southern port of Cádiz and the Canary Islands before making the 22- day voyage (Rouse 1977). It was not until 1521 that Gregorio Villalobos unloaded livestock in New Spain (Mexico) near Tampico; the actual number of cattle and their origin are disputed. Rouse (1977) claimed that 50 calves were transported to the mainland from either Cuba or Hispaniola, whereas Peplow (1958) and Wellman (1954) claimed 6 animals arrived from Hispaniola. Irrespective of the initial numbers, livestock were soon moved north from the Mexico City area during the early sixteenth century with both missionaries and resource extraction industries as retired military officers and Spanish nobility built a mining- and grazing-based economy throughout the region of present-day northern Mexico.