24/7 Trauma and Biohazard Cleanup in Penryn, CA

Penryn is a census-designated place in Placer County, about 5.5 miles northeast of Rocklin in the Sierra Nevada foothills of California's Gold Country.

Penryn began in late 1864 when Welsh immigrant Griffith Griffith established a granite quarry on a quarter-section of land leased from the Central Pacific Railroad; a rail siding was finished on February 6, 1865, and the first load of cut stone shipped less than a week later.

Griffith named the quarry after the Penrhyn Slate Quarry in his native North Wales — penrhyn means "headland" in Welsh — dropping the "h" on May 17, 1865, after discussing the spelling with Central Pacific lawyer Edwin Bryant Crocker.

At its height, the Penryn Granite Works employed more than 200 men, and its distinctive dark gray, black-and-white speckled granite was used in the California State Capitol in Sacramento and the foundation of San Francisco's Old Mint.

Penryn was home to the first granite polishing mill built in California, and the Penryn Granite Works operated from 1864 until quarrying finally ceased in 1918.

The settlement gained official standing as a voting precinct in May 1871 and got its own U.S. post office in June 1873.

Penryn had a population of 1,150 at the 2020 census, within a CDP covering just 1.9 square miles, and its households average about 2.75 people.

The old quarry site is now the 23-acre Griffith Quarry Park, and the quarry's 1877 office building houses the Griffith Quarry Museum, which opened in 1981.

Griffith Quarry was added to the National Register of Historic Places in 1977 and is also California Historical Landmark No. 885 — an unusual double honor for so small a community.