The Pembina Region (/ˈpɛmbɪnə/ PEM-bi-nə), also referred to as the Pembina District and Pembina Department, is the historic name of an unorganized territory of land that was ceded to the United States. The area included parts of what became North Dakota, and a portion of central eastern to northeastern South Dakota. The eastern boundary was the Red River, and included the Pembina River area. The region was formerly part of British Rupert's Land and the Red River Colony (controlled by the Hudson's Bay Company), that encompassed an area then known as the Assiniboia District, from 1763 to the signing of the Treaty of 1818. The treaty transferred the region that was south of the 49th parallel from the British to the United States.