There are 11 US Post Offices in Walsh County serving a total of 11,318 residents equating to 1,029 residents per post office. It's estimated that approximately 18,065 packages are handled across the 11 county post offices annually. Walsh County is a county located in the U.S. state of North Dakota. As of the 2010 census, the population was 11,119. Its county seat is Grafton. Walsh County was created by the 1881 territorial legislature and organized on August 30, 1881 from the northern parts of Grand Forks County and southern parts of Pembina County. It is named in honor of George H. Walsh (1845\u20131913), a newspaperman and politician in Grand Forks. Grafton became the county seat in 1881."