History of Los Alamos

Los Alamos is built on the Pajarito Plateau between White Rock Canyon and the Valles Caldera, part of the Jemez Mountains. The Jemez Mountains are predominantly formed by the 18.7 Ma to ~50 ka Jemez volcanic field. Volcanic activity in the Jemez Mountains culminated with the formation of two geographically coincident calderas, the 1.61 Ma Toledo caldera and 1.25 Ma Valles caldera, both of which lie to the west.

The first settlers on the plateau are thought to be Keres speaking Indians around the 10th century. Around 1300, Tewa settlers immigrated from the Four Corners Region and built large cities but were