Which two states form the entire western border of Minnesota?

A state's borders are often a fascinating mix of natural geography and political history, and Minnesota's western edge is a perfect example. This long boundary is shared entirely by two neighboring states. The northern half is defined by the northward-flowing Red River of the North, which creates a natural, winding line separating Minnesota from North Dakota. Further south, the border with South Dakota is marked by Traverse and Big Stone Lakes before becoming a straight, surveyed line running due south.

This two-state border wasn't always the case. For many years, Minnesota's western neighbor was a single, massive entity known as the Dakota Territory. This vast area, named for the Dakota people native to the region, was organized in 1861. The political landscape changed dramatically on November 2, 1889, when the federal government decided to split the territory.

On that single day, both North and South Dakota were admitted to the Union as the 39th and 40th states. President Benjamin Harrison famously shuffled the statehood papers before signing them, so no one would know which was officially admitted first. This historical event is the reason Minnesota's western frontier is now shared by two separate states, turning a single territorial line into a border with a dual identity.