 His primary area of study was the Great Basin of the United States.Heizer decided early on that more was going on in the west 10,000 years ago, although in the 1950s and 1960s it was widely accepted that there was not much going on.He had never traveled out of the United States until he went to Tabasco to work at the La Venta site in 1955, examining the Olmec society with his colleague Philip Drucker, who had contacted him about his findings there.