There are 16 US Post Offices in Dakota County serving a total of 341,123 residents equating to 21,320 residents per post office. It's estimated that approximately 544,470 packages are handled across the 16 county post offices annually. Dakota County is the third-most populous county in the U.S. state of Minnesota. As of the 2010 census, the population was 398,552. The county seat is Hastings. Dakota County is named after the Dakota Sioux tribal bands who settled in the area. The name is recorded as \"Dahkotah\" in the United States Census records until 1851. Dakota County is included in the Minneapolis\u2013St. Paul\u2013Bloomington, MN\u2013WI Metropolitan Statistical Area, the sixteenth largest metropolitan area in the United States with about 3.3 million residents. The county is bordered by the Minnesota and Mississippi Rivers on the north, and the state of Wisconsin on the east. The county was the site of historical events at Mendota that defined the state's future, including providing materials for the construction of Fort Snelling across the river and the signing of the Treaty of Traverse des Sioux which ceded land from the native Dakota nation for the Minnesota Territory. The county's history was initially tied to the confluence of the Mississippi and Minnesota Rivers, both strategically important for United States expansion and as the convergence of the Dakota and Ojibwe nations who regarded the site as sacred. Influence shifted westward during the post-World War II settlement boom when Interstate 35 connected the western half of the county to Minneapolis and Saint Paul and bedroom communities grew. Most work outside the county but like many metro counties, Dakota continues to absorb industry and jobs from the core cities."