Four Corners Monument
The Four Corners Monument marks the quadripoint in the Southwestern United States where the states of Arizona, Colorado, New Mexico, and Utah meet. It is the only point in the United States shared by four states, leading to the area being named the Four Corners region. The monument also marks the boundary between two semi-autonomous Native American governments, the Navajo Nation, which maintains the monument as a tourist attraction, and the Ute Mountain Ute Tribe Reservation.
Lake of the Woods County, Minnesota
The county contains the Northwest Angle, the northernmost point of the Lower 48 States, and the U.S. portion of Lake of the Woods, shared with Canada. The county also includes the exclave of Elm Point. Since Alaska has no counties, Lake of the Woods is the northernmost county in the United States. It is also the only county in the United States with four words in its name, although there is a parish in Louisiana called St. John the Baptist Parish, and the U.S. Census Bureau treats parishes as county equivalents for census purposes.