WHAT IS A TRINCHERAS SITE?

An Archaeological Definition

A "trincheras" site is a distinctive type of archaeological site found in the desert basins of the southwest United States and northwest Mexico. Trincheras sites are defined by:

• Location on a hill or low mountain peak
• Terraces, walls, and other constructions of local stone.

Remains of the terraces and walls reminded early explorers of "trincheras," the Spanish term for entrenchments or fortifications.

Large terrace at Cerro de Trincheras, Sonora.
Photo by Paul Fish.

Terraces and other constructions at trincheras sites are made of stones stacked without mortar. Most trincheras sites were built on volcanic hills with plentiful stones for construction materials.

Trincheras Sites Are Not All Alike

People of several different cultures in the borderlands region built terraced hilltop sites over a span of 2500 years. The earliest trincheras sites were occupied 3000 years ago, but others were occupied as late as the century when Columbus reached the Americas.

Map of Trincheras Sites in the U.S. and Mexico

A trincheras site was not an ordinary kind of settlement in any period. Most people lived and farmed in the surrounding desert basins and rarely built with stone. Trincheras sites are quite variable in size and in the numbers and kinds of man-made constructions, suggesting they all did not serve the same purpose. Archaeologists do not always agree on how to interpret these unusual sites. Based on investigations at a variety of locations, the following functions have been proposed:

• Defense
• Residence
• Terrace Gardens
• Public Events and Ceremonies
• Elevated and Prominent Location
• Visibility for Long-distance Communication
• Multi-purpose Village