The Roman Catholic Diocese of Sacramento is an ecclesiastical territory or particular church of the Roman Catholic Church in the northern California region of the United States. It comprises the counties of Siskiyou, Modoc, Trinity, Shasta, Lassen, Tehama, Plumas, Glenn, Butte, Sierra, Colusa, Sutter, Yuba, Nevada, Yolo, Placer, Solano, Sacramento, El Dorado, and Amador, and is headquartered in Sacramento, California. Also known as the See of Sacramento, it is led by a bishop who pastors the mother church of the diocese, the Cathedral of the Blessed Sacrament. Originally a major part of the defunct Grass Valley Diocese (which included several counties in northern California and Nevada), Pope Leo XIII established the present-day diocese on May 28, 1886.