Nohmul was located near the Rio Hondo. The northernmost river along the Caribbean shore, it formed a natural boundary between Mexico & Belize. Dr. Hammond has ruminated that this inlet was a major corridor from the coast into the Petén [location of Tikal & other major Maya sites] during the important Preclassic and Classic times.

Chert [microcrystalline quartz rock used for projectal points] Obsidian [volcanic glass] were two trade items that could have been transported easily by boat and/or land to numerous locations. Much of the obsidian found at Nohmul is believed to be from El Chayal, a source in Guatemala that would have been transported down the Rio Hondo. The sourcing is distinguished by chemically measuring the 10 trace elements present. The Chayal obsidian is higher in manganese, cesium, uranium & others...where the other major source, Ixtepeque is uniformly higher in iron, cobalt & hafnium.