Brownfield lies in the center of Terry County, within the southern portion of the South Plains and Llano Estacado. The city rests on a windblown deposit called the Blackwater Draw Formation, which is underlain by a thick layer of caliche, referred to locally as the "Caprock". Beneath the caliche layer lies fluvial deposits called the Ogallala Formation, which contains a portion of the vast Ogallala Aquifer. The Caprock Escarpment, about 50 miles east, forms a rather precipitous drop of about and exposes various geologic layers. In early days, climbing the Caprock Escarpment was not easy for horse-drawn covered wagons.