El Llano Estacado, with its Ogallala, caprock, playas, draws, and arroyos, has had its history determined by the land itself and will have its future shaped by it as well. Spanish conquistadores searching for gold named it El Llano Estacado, the Staked or Stockaded Plain, though whether that referred to marked trails or to the caprock’s edge looking like a distant post fort is uncertain. Dry, flat, and treeless, it was labeled the Great American Desert by early mapmakers, and the lack of visible landmarks caused even brave explorers to avoid it for fear of getting lost or dying of thirst. The caprock, named for a layer of white caliche beneath productive topsoil, is a level expanse that did not erode away as surrounding areas did. Deep below the sandy loam topsoil lies the Ogallala Aquifer, a vast underground reservoir stored in porous layers beneath the surface. Considered the world’s largest aquifer, it is being depleted faster than rain refills it, yet despite its ancient origin and the name fossil water, it still provides drinking water today. Though among the world’s flattest regions, the land has many subtle rises, and its lowest areas are playas and draws. After rains, playas appear as pools that form important wetlands within the ecosystem, while draws, or arroyos, become muddy rivers during flash floods. Though often dry and dusty, the land also produces abundant crops with water pumped from the Ogallala.