The museum's Hall of North American Mammals dioramas are considered the finest in the world. Standards were so exacting that when the hall opened in 1942 after six years of active production, only ten of its dioramas were complete. At the final dedication in 1954, there were twenty-nine dioramas on display, covering a geographic area that stretched from the Arctic Circle to Mexico and from Maine to Alaska. This hall contains two of the museum's largest dioramas: both the Alaska moose and the American bison/pronghorn antelope displays are twenty-seven feet wide by sixteen feet deep.
The curators of the Hall of North American Mammals, interestingly, limited the intrusion of text on the walls surrounding these exhibits because they did not want anything, including distracting labels, to interfere with the intended illusion of a wilderness experience.