how the west was won main title.

[Ocelot II]

12. The third one was in Omaha.

In 1961 and 1962, the Cooper Foundation was instrumental in presenting Cinerama films and film production by building three theaters to showcase the three-projector Cinerama format. There were three of these, the so-called "Golden Triangle" in Denver, Colorado, St. Louis Park, Minnesota (a Minneapolis suburb), and Omaha, Nebraska.

Although existing theaters had been adapted to show Cinerama films, The Cooper Foundation designed and built three near-identical circular "super-Cinerama" theaters. They were considered the finest venues to view Cinerama films. The theaters were designed by architect Richard L. Crowther of Denver, a Fellow of the American Institute of Architects. The original blueprints for the theater are in the Denver Public Library Special Collections Department.

Crowther designed each element of the theaters to enhance the Cinerama experience. The circular design took advantage of the discovery that patrons, if left to their own devices, would seat themselves in an oval pattern. The exterior circular shape served as a constant reminder to passing motorists that this was a Cinerama theater. The design included a cylindrical shape and a flat roof.

https://en.wikipedia.org/wiki/Cooper_Foundation