The McCook Library, listed on the National Historic Register, is an example of the Spanish Colonial Revival style, designed by architect William A. Marean of Denver, Colorado. Marean designed numerous turn-of-the-century buildings of prominence in Denver and the surrounding area, but the library building in McCook is the only structure in Nebraska known to have been designed by him. Property for a building site was donated by a local firm, and Andrew Carnegie provided construction funds in December of 1905. The library was dedicated on February 17, 1908.