This article presents results of neutron activation analysis of near eastern obsidian found in contexts dating between 7500 and 3500 B.C. Na/Mn ratios were found to separate groups pertaining to different source flows in the region of Lake Van, Eastern Turkey. Sites in the Zagros-Taurus arc were obtaining obsidian from Lake Van sources prior to the Hassuna phase (5800-5200 B.C.). Obsidian from one of the Lake Van groups was found in the Levant in preceramic Neolithic contexts dating around 7000 B.C. This evidence suggests a route for the movement of early domesticated wheat out of the Jordan watershed. Some shifts in source utilization through time were noted for sites in Greater Mesopotamia. By 4000 B.C., about half of the obsidian in the Levant originated from Lake Van sources.