Almaden Quicksilver County Park

Quicksilver Relics at New Almaden on the Ridge Trail

The Bay Area Ridge Trail winds past the remains of California’s oldest commercial mining operation at Almaden Quicksilver County Park. The trail segment runs across land first tapped for its mercury content in 1845. Look for the partially reconstructed ruins of a 20th-century processing plant trailside above English Camp and other buildings in the surrounding hills and valleys.

We are hiking the 405-mile Bay Area Ridge Trail. Sign up to follow our progress here.

TRAIL MAP (date hiked)

  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park
  • Almaden Quicksilver County Park

Our Journal

Every segment of the Ridge Trail holds a surprise. An opportunity to check out a rebuilt Rossi Retort amid the ruins of a mercury processing plant in a park that encompasses the historic community of New Almaden qualifies.

Miners had been extracting mercury-rich rock in the region for nearly 80 years when Louis Rossi came to town in the 1920s. He introduced his retort as a means to speed up the extraction of mercury from the local ore.

Here’s how it worked, according to the signage on site:

Trucks would dump mercury-laden rock from the mines through a size-regulating knife gate into a pair of cylinders. The rocks could measure no more than three inches. As the ore heated, condensation pipes captured mercury vapor. As the vapor cooled, the mercury reverted to a liquid and drained into rubber buckets filled with water. The retort was rebuilt and dedicated in 2014.

The history of the mining operation in the 20th century is a bit muddled online. The National Park Service says the Quicksilver Mining Co. declared bankruptcy and closed in 1912, and then abruptly ends its history lesson. Yet the signage in the park describes the arrival of the Rossi Retort in the 1920s and processing operations during World War II.

We might have figured it out with a stop at the Almaden Quicksilver Mining Museum adjacent to the park, but the 170-year-old hacienda – Casa Grande – that houses the museum is closed for some HVAC work.

Quicksilver aside, we also not met a friendly young hiker who was enjoying her weekend off from a newly acquired post at a Bay Area biotech firm. We hiked and chatted with her for several miles. It’s always special to make a new friend on the trail.

Miles we hiked


(with returns and connectors)

Elevation gain






Our Progress Hiking the Bay Area Ridge Trail – 325 out of 405 miles


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