Descendants of more than 60 tribes make Oklahoma second only to California in Indian population. In the early 1800s the region was established as Indian Territory, a vast reserve for displaced Native Americans. The eastern Indian Territory remained separate until 1906. Eventually land-hungry farmers swallowed up Indian Territory, and Oklahoma was born in 1907. This state of "soil, oil, and toil" has weathered hard times. The droughts and dust storms of the Depression years forced Okies westward in desperate search of work. The state's economy has been broadly diversified from its traditional oil and agriculture base. Natural gas production, machinery manufacturing, and food processing are among the leading industries.