Located in the northwestern portion of Idlewild Park, the California Building is the only remaining architectural element of the Transcontinental Highway Exposition of 1927. Idlewild Park was created for this exposition, which celebrated the completion of the Lincoln and Victory highways (present day U.S. 50 and U.S. 40). In 1913, members of the automobile industry began raising money to create a hard-surfaced highway coast-to-coast, with accurate signs along its entire length. The Lincoln Highway Association was formed that same year to help complete this early transcontinental highway, and with the assistance of the Federal Highway Aid Act of 1916 and 1921, their goal was soon reached.
The completion of the highways opened up Nevada to the lucrative automobile tourism trade, and led to growth and development of communities along the highway routes. The Bay Area landscape architect Donald McLaren, who had designed the landscaping for the 1915 Pan-Pacific Exposition in San Francisco, developed the layout for Reno’s exposition. The California Building was a gift from the neighboring state of California, which spent two years and $100,000 preparing the building and its exhibits for the Exposition.
The California Building was constructed in the Mission Revival architectural style, appropriate as a representation of California’s Spanish and Mexican heritage, with the style-defining features of stuccoed walls, clay tile roof, a bell tower, and arched openings. The California Building was the grandest exhibit at the exposition, paying homage to those who fell in combat in World War I. The California legislature dedicated the building "To the memory of those who gave the last full measure of devotion to this nation."
During the Exposition, specific days were dedicated to celebrating individual California cities inside. San Francisco promoted its port and tourist attractions, while Los Angeles devoted much space to its budding movie industry.
After the Exposition, the structure was presented to the local post of the American Legion. Today, the California Building stands as a reminder to Nevadans of their role in early transcontinental highway development. Listed in the National Register of Historic Places in 1992, it is currently owned by the City of Reno and is used as a recreational and community-use facility.