It was first excavated by Junius B. Bird in 1946–1947 who excavated three large test pits in or beside it. The remains, now at the American Museum of Natural History in New York City, include many examples of complex textiles made with twining techniques which incorporated intricate designs of mythological humans, condors, snakes and crabs. The many stone artifacts were not fancy—fish net weights, flakes and simple pebble tools; there were no projectile points. In the upper part of the mound there were many underground structures of unknown function, some with burials. They were made of cobblestones cemented with an ash-water mixture. The inhabitants fished, gathered shellfish, and grew fruit, gourds, squash, peppers, beans, tubers and, importantly, cotton.
There is a low mound 70–170 m to the north (now called Monticulo Cupisnique) where Bird excavated three test pits. He found many ruins and much refuse, including ceramics of the Guañape, Early Cupisnique and Cupisnique cultures. The last is linked to the highland Chavín culture. A large tsunami damaged both mounds leaving a thick layer of cobblestones just north of the preceramic mound, at about 850 BCE, between the two Cupisnique phases.
Until recently, it was beilieved that maize was introduced to the region rather late, after the tsunami.
In 2012, it was reported that corncobs found at two ancient sites in Peru (Paredones and Huaca Prieta) may date from as early as 4700 B.C. This suggests that people living along the coast of northern Peru were already eating corn by that time.
These results were reported by Dolores Piperno, and other scientists from Washington's National Museum of Natural History This is the earliest maize discovered so far in South America.
^Sigfried J. de Laet, Ahmad Hasan Dani, eds. (1996). History of Humanity: From the third millennium to the seventh century B.C. History of Humanity: Scientific and Cultural Development 2. UNESCO. p. 1100. ISBN92-3-102811-1.
^Clark, Grahame (1977). World prehistory in new perspective (3rd ed.). Cambridge University Press. pp. 432–433. ISBN0-521-29178-X.
^Grobman, A.; Bonavia, D.; Dillehay, T. D.; Piperno, D. R.; Iriarte, J.; Holst, I. (2012). "Preceramic maize from Paredones and Huaca Prieta, Peru". Proceedings of the National Academy of Sciences109 (5): 1755. doi:10.1073/pnas.1120270109.