Hand-carved arrowheads and jagged spears made of obsidian, a sharp rock formed by volcanic magma, are remnants of vast prehistoric trade networks that once cut across western North America. New ...

Some of the obsidian artifacts, including arrowheads and spear tips, traveled nearly 750 miles from their source, according to Allan. An obsidian spear head from the Red Deer area. Photo by Todd ...

Archaeologists have evidence for long-distance trade routes across North America that could totally rewrite previously ...