Quicksilver Mines off Curtner Avenue

I grew up near Curtner and Almaden Expressway, right up against a group of hills historically known as the San Juan Bautista Hills, now more generally referred to as Communications Hill. The hills are the home to "The Church on the Hill," Santa Clara County Communications, and Oak Hill Cemetery. Although I was aware that old mines existed in the hills, I didn't get around to actually exploring them until fifteen years ago. I was able to take and gather a number of photos of the mines and took some video of a smaller mine before they were all permanently sealed. Video of the smaller mine appears below. 

Mexican Mines from 1847

Commonly known as the Hillsdale Mines, the mines were located along the east side of the County Communications hill. This outcropping of hills are composed of metamorphic rock, largely serpentine, with veins of reddish cinnabar ore. When the ore is crushed and roasted, it produces liquid mercury (quicksilver) that has many uses.  Mexicans began mining the cinnabar at this location about 1847, stopping 1861 when they hit a spring which flooded the lower tunnels.  From 1862 to 1874 the mines were operated by a fellow named Chapman who in 1871 was producing 30 to 40 flasks of mercury a month.  The mine continued operation off and on over the next fifty years with the final serious efforts in the late 1930s.       

Lost in the Mines!

On Friday, July 27, 1962, Willow Glen high student Dale Patrino, her boyfriend Jim Butters, and his friend Mike Atchison all decided to wander around the hills where Dale lived. She lived on Carol Drive, the road that lead to the Santa Clara County Communications on the highest peak of the San Juan Bautista Hills just east of Willow Glen. Taking Dale's younger brothers Rob (9) and Wayne (4) with them, the group set off and were seen at the nearby Ironwood Swim and Golf Club around 1 pm.  Around 4 pm, the group had decided to explore the old mercury mines on the east side of the County Communications hill.  The youngest of the group was my classmate Wayne, who shared his memories of the event years later, "We went down into kind of an open room...and there were catacombed trails, caves going in different directions from the main room."

The group ventured along one of the tunnels using candles that Rob had brought along. After about a half hour, they decided to head back out but just couldn't find their way. In time, their candles gave out and they continued to wind their way through treacherous passageways using only the light from lit cigarettes.  When these gave out, they gave up and decided to stay put. In the meantime, Wayne's mom had called out "the cavalry."  Suspecting that the group may have entered the mines, County Sheriff's Sgt. Tom Rosa and deputies enlisted the aid of 17-year-old Dennis Percy, a neighbor who knew the mines well. Nine and a half hours after entering the mine, the group was located huddled together in a small branch tunnel about 450 feet from the entrance.   

Video:  Part 3 of a three-part series of videos about the Hillsdale Mines on my Youtube channel Garden City Days of San Jose.  In the 2009 video, my son's friend joins me in exploring the interior of the last open Hillsdale mercury mine (now closed).  Video by Ralph Pearce

Further Reading from the California Room:

• Report...of the State Mineraligist by the California State Mining Bureau
• Mines and Mineral Resources of Santa Clara County California by Fenelon F. Davis and Charles W. Jennings
• Hillsdale Mercury Mine Near Willow Glen in San Jose Part 1 by Ralph Pearce
• Hillsdale Mercury Mine Near Willow Glen in San Jose Part 2 by Ralph Pearce