The DOI org chart is commonly referred to as the United States Department of the Interior. The organization's primary responsibility is to protect and manage various natural resources and cultural heritage in the United States of America. The following DOI org chart provides a quick overview of the overall structure of DOI. The Department of Interior's service groups ranges from American Indians to affiliated island communities. So far, the organization has over 70,000 employees and nearly 300,000 volunteers, among whom are scientists and natural resource researchers. Furthermore, the DOI raises billions of dollars from other American federal government agencies each year.