There are no written records of Olmec commerce, beliefs, or customs, but from the archaeological evidence, it appears they were not economically confined. In fact,
Olmec artifacts have been found across Mesoamerica, indicating that there were extensive interregional trade routes.
The presence of artifacts made from jade, a semiprecious green stone; obsidian, a glassy, black volcanic rock; and other stones provides evidence for trade with peoples outside the Gulf Coast of Mexico:
the jade came from what is today the Mexican state of Oaxaca and the country of Guatemala to the south; the obsidian came from the Mexican highlands, to the north.
The Olmec period saw a significant increase in the length of trade routes, the variety of goods, and the sources of traded items