What feature of the California-Intermountain environment best explains the Pomos and rsquo use of clamshells for jewelry?

The abundance of clamshells in the California-Intermountain environment likely influenced the Pomos' use of clamshells for jewelry. These shells were readily available and easily accessible, making them a common material for crafting adornments. The Pomos creatively utilized the resources in their environment to create beautiful and meaningful jewelry pieces.