This article begins with a description of excavations in the Las Vegas type site on the Santa Elena Peninsula, Ecuador. A pre-Las Vegas phase (11,000 to 10,000 B.P.) is defined provisionally, and the Early Las Vegas (10,000 to 8000 B.P.) and Late Las Vegas (8000 to 6600 B.P.) phases are described from artifacts, burials, settlement data, faunal remains, pollen, and phytoliths. The Las Vegas people were unspecialized hunters, fishermen, and gatherers living in a littoral zone who added plant cultivation to their subsistence system before 8,000 years ago. Evidence for bottle gourd (Lagenaria siceraria) and primitive maize (Zea mays L.) was found in the Las Vegas type site. The differences between the modern, semiarid environment and the environment of the preceramic period are accounted for without hypothesizing climatic change. Las Vegas is interpreted as a local manifestation of an early tropical forest cultural tradition out of which developed the ceramic-stage cultures of the Ecuadorian coast.