Grand Forks is a city in northeast North Dakota and serves as the county seat of Grand Forks County within the United States. Situated on the western banks of the north-flowing Red River of the North, it lies in the flat region known as the Red River Valley, which was formed by the ancient Lake Agassiz. The city forms the center of the Grand Forks metropolitan statistical area alongside its twin city, East Grand Forks, Minnesota, often referred to collectively as Greater Grand Forks or the Grand Cities.