by April M. Brown
SPECIAL NOTE: The Archaeological Conservancy would like to remind our readers that the collection of artifacts from archaeological sites is illegal and irresponsible. When visiting cultural sites, please do not remove or disturb artifacts.

We all enjoy corn on the cob during our summer barbeques, but do you ever wonder how this sweet and delicious grain came to be? Maize agriculture made it into the American southwest around 3,000 years ago and continues to be practiced in Pueblos today. Maize is derived from a tropical grass called teosinte that was cleverly cultivated and engineered by Indigenous people in Mexico thousands of years-ago to create the versatile staple crop we roast and butter today. Teosinte did not produce cobs or edible kernels, so the evolution of this grass into a cob-producing staple crop is quite an amazing feat. The evolution of maize continues to be a popular research topic in anthropology and archaeology and there are numerous DNA studies that discuss the origin and migration of the plant from Mexico into North America.
Maize is part of the “Three Sisters” – a trifecta of staple crops grown by the Indigenous people of North America that also includes squash and beans. The kernels were ground into flour using mano and metate grinding stones, and the cobs were stored in sealed pots and baskets for use during times of food scarcity. Maize was central to the sustainability of Indigenous cultures dating as far back as the Archaic period.

Ancient cobs are found at archaeological sites across the American southwest. Heritage strains of maize were much smaller than modern corn with some only measuring three to four inches in length, such as these examples from Wells Petroglyph Preserve, a Conservancy site in northern New Mexico, and Tsankawi, a National Park site located near Los Alamos, New Mexico.
We discovered these examples at Mesa Prieta during the filming of our recent Virtual Tour Video of Wells Petroglyph Preserve. The first cob was found on top of the mesa where there is evidence of waffle gardens and irrigation ditches still visible on the surface. The second cob was discovered as we traversed the basalt terraces on the eastern side of the mesa which overlooks the Rio Grande.
The examples from Tsankawi were discovered during my fieldwork with the University of New Mexico in the summer of 2019. As we were documenting cavates in a remote area of the park, we discovered a carved spiral petroglyph and a crevice with cobs spilling out into the sand.

There were dozens of cobs ranging from two to four inches in length. I imagined that the cobs were stored in a jar or basket that had returned to the earth after hundreds of years, spilling the contents into the sand for animals to disperse. All of these examples are most likely from the Ancestral Pueblo period sometime between 1200 and 1500 A.D, although testing would be needed to confirm the actual dates.
Caches of ancient maize are found across the southwest, especially in places like Utah, where the conditions are more favorable for the preservation of these normally perishable artifacts. In northern New Mexico, the conditions are not always so favorable. The occasional discovery of these tiny cobs in the sand are a small reminder of how important this crop was to the survival of Pueblo cultures hundreds, and even thousands, of years in the past.
So, as you enjoy your grilled corn on the cob this summer, remember its humble beginnings as a tropical, Mexican grass, and the time and work that ultimately produced those large, juicy cobs we grow and buy today.