The Fox Theater at 3rd and Garey opened in 1931--that's the opening day picture at left. It cost $350,000 to build and had the first refrigerator air conditioning east of Los Angeles. (Pomona is still in the county, of course--cuz that's where the Fair is.)
The building was put on the National Register of Historic Places in 1982. Since 2000, the city of Pomona has been the owner of record, and Pomona Heritage is leading an effort to restore the Fox Theatre to its Depression Era glory. In those days, stars like Shirley Temple and Bob Hope used to appear at preview screenings of their films at the Fox, which was just far enough from Hollywood to reflect middle-American tastes. Besides the special appearances, movie stars and producers would be in the audience as well.
These pictures come from Pomona Heritage'swebsite about the building's history. In 1938, for example, all of Los Angeles and San Bernadino Counties suffered through terrible floods. The Fox Theatre, big enough to hold an audience of 1500 people, served as a shelter for 300 refugees.