09/04/2026
The Placer County Administrative Center was built in 1966 on Fulweiler Avenue in Auburn and is a remarkable example of innovative mid-century modernist design. It is comprised of five geodesic domes with an open framework dome positioned over the entry plaza with a fountain centered beneath. The roof is covered with a golden finish to represent the county’s gold rush-era roots while the overall shape emulates the low rolling foothills of the region.
Commonly known as The Domes, this structure along with the two-story concrete building next door, represented a new era for Placer County. They were originally planned to ease overcrowding at the courthouse where the administrative functions of the county had always operated. The site was selected near the courthouse. Here, Placer County purchased 22 acres of vacant land and between 1963 and 1966 built these two structures.
The geodesic design was chosen for cost efficiency expected in the prefabricated project. The entire structure was made in panels of anodized aluminum at the Temcor facility in Torrance, California. Shipped by rail, the first dome took three weeks for crews to complete. After this initial learning phase, it took only about three days to assemble each dome with the entire project taking 10 months at a total cost including landscaping, of $689,648.47.
At the dedication ceremony on Oct. 29, 1966, Board of Supervisors Chairman Will Jones, remarked: “To me these new buildings represent new thinking. They represent the ability to gain from the experience of others. They are a new approach and, as I like to think a new start.”
Today, this unique structure has been carefully maintained and in 2025 was added to the National Register of Historic Places for its architectural significance.
If anyone has a photograph of The Domes under construction or when newly built we would love to see it!
Image: Architect's rendering of Placer County Administration Building, published in Placer County Reports newsletter, Vol. 1, No. 3. October 1966.
