15 Indigenous Foods That Shaped The American West MarieKaz/Shutterstock If you've ever wondered what exactly constitutes the American West, it's essentially everything west of the Great Plains. According to the U.S. Census Bureau, that includes Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Sometimes that definition expands to Texas, and any other state located west of the Mississippi River.