The Utah State Historical Society: Rio Virgin Chapter, was created in 1970. It was the first Utah State Historical Society chapter in Washington County. It was created under the administration of Charles S. Peterson of the state historical society. He worked on an expansion movement for the historical society's chapters and added three new groups.
The chapter’s purpose was for the collection, preservation, interpretation, and dissemination of historical, archaeological, and geological knowledge; the gathering and preservation of historical documents, materials, and relics about the past; writing the history of the area and its peoples; and, in cooperation with the Utah State Historical Society, furthering the gathering, writing, and dissemination of historical knowledge about Utah and of the Washington County regional area.
In 1982 the Rio Virgin Chapter was reorganized and became the Washington County Historical Society.