The Diocese, or ecclesiastical territory, is composed of 22,127 square miles [57,287 square kilometers], decidedly rural and embraces 38 counties in northeastern and central Missouri. It includes the urban areas of Columbia, Hannibal and the State Capital of Jefferson City. The Diocesan patroness is the Immaculate Heart of Mary. It is located in region IX of the United States Conference of Catholic Bishops (USCCB).