Pembina County, ND borders Walsh near Cavalier metropolitan centre granting a 2020 estimated census population standing at 7,904 making it the 8th most populous county located in North Dakota overall. Its county seat is Cavalier with other cities include Pembina & Mountain-Cavalier itself corresponds out to Pembina's largestcity aside from noted country seat. This area had been created from Walsh and Ramsey Counties back in 1867 when local citizens petitioned for new administrative boundaries - posthumously named after Canadian provincial capital city Pembina there standing adjoining region prior era Andrew Johnson .