The Johnstown Flood Museum plays an important role in documenting the tragedy and loss of the flood. The museum also hopes that preserving the knowledge of the flood can assist future generations in averting similar disasters. The museum is located in the Cambria Library, an ornate three-story French Gothic structure that was erected following the flood to replace the previous library. Steel magnate Andrew Carnegie donated the funds to build the library. The building served as the city's library for seven decades and became home to the Johnstown Flood Museum in 1973.
The museum contains several exhibits that educate visitors about the flood. One such exhibit is an electronic relief map of the flood. Sound effects and lighting are used to illustrate the path of the flood, as well as its effects. There are also some examples of cultural reactions to the flood, such as artwork and movie posters. Additionally, many physical artifacts from before and after the flood can be viewed, such as a bottle of water from the flood, debris, or a morgue book.
Perhaps the most significant of these is the Oklahoma House. Many structures known as Oklahoma houses were built after the flood, in order to shelter the thousands of homeless tenants. Before, many were living in tents and shanties. The Oklahoma House is an original from the time of the flood. It was donated to the museum by Habitat for Humanity after the organization learned of the historical importance of the house.
In preparation for the centennial anniversary of the flood, JAHA commissioned the internationally acclaimed filmmaker Charles Guggenheim to produce a documentary on the flood to be shown at the museum. The 26-minute film won the Academy Award for Best Documentary, Short Subject. The film uses JAHA photo archives and recreations of events and is shown every hour at the Johnstown Flood Museum, in a specially-designed theater located on the second floor. In recent years, the film was converted from to digital and captions were added so that deaf or hearing impaired visitors can also view the film.