Chico river basin 

A set of glass endscrapers has been recovered near a ranch house.

These artifacts are characterized by a wide variety of shapes, sizes and colors. These differences are related to the specific characteristics of the container from which they were made.

The craftsmen chose glass based on its compositional characteristics, which are similar to those of a well-known raw material: obsidian. Being suitable for flintknapping, the glass could be worked using traditional techniques.