The Archdiocese of Portland in Oregon (Archidioecesis Portlandensis in Oregonia) is an archdiocese of the Roman Catholic Church in the Pacific Northwest region of the United States. It encompasses the western part of the state of Oregon, from the summit of the Cascades to the Pacific Ocean. The Archbishop of Portland serves as the Ordinary of the archdiocese and Metropolitan of the Ecclesiastical Province of Portland whose suffragan dioceses cover the entire three states of Oregon, Idaho, and Montana. The dioceses of the province include Baker (eastern Oregon), Boise (Idaho), Helena (western Montana), and Great Falls-Billings (eastern Montana).