Following the settlement of the West Coast (California and Oregon) in the 1850s, the Great Plains was the last frontier for American pioneers. Native Americans of the Great Plains utilized the resources of the region without causing any real change to their environment for thousands of years. Plains Indians relied on the buffalo for all aspects of life including food, clothing, tools, shelter and religious worship. They wasted nothing and only killed what they needed. Native Americans of the Great Plains utilized the resources of the region without causing any real change to their environment for thousands of years. Plains Indians relied on the buffalo for all aspects of life including food, clothing, tools, shelter and religious worship. They wasted nothing and only killed what they needed.