North Dakota Heritage Center

From the Wikipedia page

The North Dakota Heritage Center & State Museum, located on the North Dakota State Capitol grounds in Bismarck, is the state of North Dakota's official history museum. The original building, which was opened in 1981, is operated by the State Historical Society of North Dakota and features permanent and temporary exhibits. In June 2008, the museum, which has been called a "Smithsonian on the plains", became home to a rare mummified Edmontosaurus with fossilized skin.

Expansion of the North Dakota Heritage Center & State Museum finished with a grand opening on November 2, 2014, coinciding with the 125th anniversary of statehood. The expansion added 127,000 square feet of collections storage, labs, and office space, doubling the total size of the museum.