Tuesday, March 31, 2015

The Footprint of the Winged Sandal: The Mercury Mine of Almaden Quicksilver

Date: Mid-January through the end of March, 2015
Place: Almaden Quicksilver County Park, San Jose, California
Coordinates: 37.173951, -121.825087
Length: about 4.1 miles
Difficulty: moderate

A long time ago Papa Quail visited a hi tech company in San Jose. He then told me that there is a nice park nearby where wild turkeys roam free. Years after when we moved to the Bay Area I remembered that somewhere in Almaden there is a nice park and made myself a mental note to check it out.

Almaden Quicksilver is a nice park. A very nice park. It has beautiful landscape, fascinating wildlife, gorgeous spring show of wildflowers and miles upon miles of trails for hiking and biking.
But Almaden Quicksilver is more than all that. It is IMHO one of very few Bay Area parks where the history of human activity is so fascinating that it adds to the attraction of the place despite the disturbance to its Nature.

There are several trailheads around the park and I selected the Mine Hill trailhead, leading to English Town, and returning by the steep Deep Gulch Trail.

My hike at Almaden Quicksilver CP as captured by Pappa Quail's GPS, with Mine Hill Rd shortcut added in brown. 
Where is now a beautiful park used to be a large mercury mine. About 100 yards up Mine Hill Trail there is a nice view on Alamitos Creek Valley and the green meadow where just a few decades ago used to be a a large mercury reduction factory. Mining leftovers were removed when the area was added to the Santa Clara County Parks.

Imagine this flat as a bustling mercury recuction factory.
Information plaques with historical information are placed at various points in the park. There is one at the Alamitos flat overlook as well. An informative and interesting exhibit of the mining and reduction machinery is located at the edge of the meadow. The loop trail ends at the bottom of Deep Gulch, behind that exhibit. On the way back to the car it is very compelling to stop at the exhibit and inspect it closely. It is a fascinating display and is very well done.
Mercury mining and reduction display
Mercury, or by its common name: quicksilver, combined with sulfur on the way up ancient volcanic chutes. The mercury-sulfur combination is the reddish mineral cinnabar. Cinnabar-containing rocks were grounded to a powder and baked in retorts. The molecules would split and the elemental sulfur and mercury become gas. The sulfur would evaporate away but the mercury fumes would be captured and cooled. Being liquid at ambient temperatures, the mercury would condense and drip into iron flasks and be shipped away to where it was needed most: the gold and silver mines.

My first visit there was in January. The rains have stopped prematurely in December and the temperatures were on the rise. Springtime begun way too early for 2015. It was evident from the plants that were budding all over the place.
A springtime ephemeral: Milkmaids (Cardamine californica)
It was the beginning of Bay Area wildflowerfest. And deciduous trees were following close behind.
Budding California Buckeye (Aesculus californica)
Poison oak is very common along the trail I hiked. Most of the way though it is far enough to be a concern. Left untouched, it is very beautiful to see. Especially in its red, new spring foliage.
Poison Oak (Toxicodendon diversilobum)
I hiked that trail several more times through the month of February and the beginning of March with my hiking groups. As springtime set in I witnessed the progression of bloom as more and more species opened their colorful sexual advertisements, calling the pollinators to deliver.
Padre's Shootingstar (Dodecatheon clevelandii)
Mine Hill Trail is a wide and convenient gravel road that leads uphill to English Town and beyond. In the days of the mine it was an actively used radon which vehicles were going up and down the hill. Two of these vehicles ended off road, half buried in the dirt. These cars enticed the children in the group who speculated about the various ways in which these cars found their fate and on what might have happened to the people inside.

Anyone recognizes the make and model?
Old Mine Rod provides several vista points to view Mount Hamilton that are just perfect. Mount Hamilton, the highest mountain in the Bay Area, is home to the Lick Observatory (those white marble-like structures on the summit). On its western slopes there is Joseph D. Grant County Park, another splendid place to go hiking.
Mount Hamilton and the Lick Observatory
As I was pointing Mount Hamilton to my fellow hikers Papa Quail caught up with me and pointed at a black dot that was circling the skies above. Large, dark-looking raptors in the area are usually turkey vultures that are fairly common. But not always. This one was a golden eagle. Always foot to look up through the binoculars.
Golden Eagle (photo by Papa Quail)
Looking down one also finds interesting things. This spider trap, for example.

Or the delicate flowers of another spring ephemeral, the pacific hound's tongue.
Pacific Hound's Tongue (Cynoglossum Grande)
At the end of January there was still much dampness on the mossy ground and rocks. Moss, lichen and budding ferns coated the hillside under the trees.
A little over a mile uphill there is a trail intersection with a picnic table. A perfect rest stop. On my first solo hike I continued straight up Mine Hill Trail but on following hikes we took the turn to Randol Trail all the way to Day Tunnel. A spectacular view of Santa Clara Valley (a.k.a. Silicon Valley) spread below. All the way to the north - that shadowy bump in the horizon to the picture's right - the silhouette of Mount Tamalpeis. And that photo was taken on the best of view days. On most of my hikes the air was so soupy we couldn't see any horizon at all and the north part Silicon Valley just faded into hazy nothingness.
Valley of Santa Clara (a.k.a. Silicon Valley)
The north-facing hillside is shaded and cool. It was very green and throughout February more and more plants came to a nice bloom, giving a strong competition to the fine view of the valley.
Bluewitch (Solanum umbelliferum)
I was happy to see the crimson Indian Warrior decorating the hillside.
Not too far from the brighter red Indian Paintbrush :-)
Indian Paintbrush (Castilleja affinis)
I also run into a familiar garden herb - a lush peppermint shrub. I was very tempted to harvest some for my afternoon tea but held back on that urge.
Peppermint (Mentha x Piperia) a hybrid non-native herb
There was only one peppermint plant there, but a lot more of the invasive sourgrass weed, a plant that is spreading more and more throughout the Bay Area.
Sourgrass (Oxalis pes-caprae)
After 10 minutes on Randol Trail I reached Day Tunnel. The tunnel itself is blocked but the old mining rubble is clearly visible still where it was being dumped for over a century.
Day Tannel
Cinnabar, the reddish mercury-sulfur mineral containing rock was the prized treasure mined at New Almaden. Cinnabar stones are still visible along Mine Hill Trail and Randol Trail, embedded by years of treading tires, hoofs and feet. It was mercury, not gold, that had made this mine so profitable. It is the mercury mining waste that makes the fisheries of the nearby lakes unsuitable for consumption.
Day Tunnel is named after Sherman Day, the mine's engineer in the late 1880, who advised digging that tunnel. At the time of the mine's peak operation the majority of the mined cinnabar was taken through this tunnel.
Nowadays water seeps through, creating a small, shallow pond that collects into a tiny trickle down the gulch.
The Day Tunnel pond
I wouldn't drink that water, but the resident California Newts have no alternatives. 
And there were many, many newts at that pond at the end of January. In fact, it was the most dense group of newts I have ever seen.
California Newt, female
Thy grouped there for a reason - to procreate.
A pair of California Newts in action
There were so many of them, in pairs and in wrestling groups, that the entire pond was bubbling with sexual activity.
Newt orgy
I sat there for a while, fascinated by that spring activity. Later I brought my hiking group to that place. The newts were still there, but in smaller numbers. They also seemed less enthusiastic all and all. And on my last hike in Almaden Quicksilver at the end of February the gate to Randol Trail was closed for the season, diverting me to continue on Mine Hill Trail. A park ranger later told me that the trail had been closed due to muddy conditions. I assume it is all the best for the baby newties growing there to be left in peace.
From there I took the steeper Day Tunnel Trail and Great Eastern Trail up to meet Mine Hill Trail once more. That trail is narrow, steep and shaded with majestic old laurels and coastal live oaks.
The big laurels didn't fit in the picture so I post the oaks
The trail passes along piles of mining rubble that are so old they have already grown green with moss and were hard to discern from the natural rocks by the trailside.
By the end of February the laurels were blooming too:
California Laurel (Umbellularia californica)
I spotted eucalyptus along the trail. Eucalyptus can be very majestic and beautiful too. They are, of course, not native to California at all. Brought hither from Australia they took hold and spread themselves all over the Bay Area and are pretty much impossible to remove.
Blue Gum (Eucalyptus globulus)
Near the top of the Great Eastern Trail there are a few interesting quartz rocks, proving that there is more to Almaden Quicksilver geology than cinnabar.

Back on MIne Hill Trail again I turned left toward English Town.
The presence of the reddish rock was known to the Native Americans in the area and the local rancheros, but it was the Mexican cavalry captain Andres Castillero in 1845 that identified it as cinnabar and recognized its value. At that time the biggest and most profitable mercury mine was in Almaden, Spain, so in a very original fashion, the place was named New Almaden.
Three years later the U.S.A. has conquered California but other than one attempt to nationalize the mine during the civil war, the government pretty much left the mine in private hands. Most of the time - in the hand of Almaden Quicksilver Mining Company.
There were two mining towns up Almaden Quicksilver where the mine workers lived. My trail took me through English Town.
A building in English Town
The town was a lively place with residencies, a church and a school. The residents leased their houses from the mining company and left when the company closed.
Today both towns are ghost towns.
Church site at English Town
There is a clearing there with picnic tables. A perfect place to rest after the ascend and to have a demonstration (using a harmless model system) of how they used to separate gold from the ore in those days.
Tens of thousands of people flocked to California to look for gold during the gold rush. Many sifted gold from the rivers but most of the gold was excavated from the rocks and had to be separated from the ore. And the only way to do so efficiently that was known in that time was through a process called amalgamation. A process that necessitates mercury. The same process was used to purify silver too.

Mercury binds gold, or diver, creating a compound called amalgam. As the gold miners mixed the ore with the mercury an amalgam would form and, being lighter than amalgam, the rock waste would float and separated. Then the amalgam would be cooked to boil the mercury away, leaving pure gold (or silver) behind. The mercury vapor would then be trapped and cooled back to a liquid for reuse.
Mushroom clouds 'sprouting' from the hilltop
Mercury is much rarer in the Earth's crust than gold or silver and there are very few high-quality mercury mines in the world. New Almaden was one of them. It was more profitable than any gold mine. In fact, it was the most profitable mine in California.
And then, in the early 20th century, a new method for purifying gold and silver was found. The price of mercury plummeted and eventually the mine closed.

After a good rest I continued on Mine Hill Trail over the hill and down. Pretty oaks decorate the hill that towers over the trail. one of them was dead and fallen.

The Gripping Hand
It looked like a skeletal hand reaching out of a grave, or something like that. I called it 'Thing' and was glad for the bright sunshine.
Papa Quail looked more carefully in the trees and followed the chirps to their source.
Yellow-rumped Warbler (photo by Papa Quail)
From Mine Hill Trail I turned right into Deep Gulch trail. In the beginning, this trail is as wide and easy as Mine Hill Trail. This luxury ends at the First Tunnel.

Appropriately named, this was the first horizontal tunnel that was dug in the mine. Also blocked, the tunnel is marked by the big pile of mining rubble that was dumped at its mouth.
First Tunnel
From there, Deep Gulch Trail plunges into the deep shade of the woods as a narrow and steep foot trail .
Descending into Deep Gulch
Still damp from December rains, Deep Gulch Trail sported many mushrooms. Some were quite spectacular.
Turkeytail fungus
Some were not as flashy, but nevertheless interesting.

Annulohypoxylon thouarsianum
There is a lot of poison oak along that trail, and more of the already familiar woods wildflowers like the milkmaids and the hound's tongue. Tiny white flowers caught my eye and after some effort I managed to take a descent photo.
Common Chickweed (Stellaria media), non-native
And one more tiny photo challenge :-)
Birdeye Speedwell (Veronica persica), non-native
Down and down that trail goes, and it's very hard to resist running it. When I took the group nearly everyone had passed me galloping downhill. I clumbered along slowly, that's how I came to see this beauty:
Checker Lily (Fritillaria affinis)
It was the only plant of that species I could see on that slope and it didn't fit any of the fritillary photos on Calflora so after I got home I asked my knowledgeable friends of the California Native Plants Society. Most responses identified this as a Fritillaria affinis. There was some dissent, however, and a discussion of the non-affinis traits of that flower. I volunteered the gps coordinates of the plant to whomever would be willing to go and take a personal look and, sure enough, I was asked to provide those coordinates. I opened the file and my heart sank: my camera's gps had not locked on the satellites the entire hike. I had no coordinates to provide. Gritting my teeth, I put off another commitment I had and drove back to Almaden Quicksilver, rushed uphill (the plant was on the upper part of Deep Gulch Trail!) and found it!  This time I brought not only my hand-held gps but also took the car's navigator along, just in case. This time I did run down hill (I had to be back on time to pick up the chikas from school), and delivered the coordinates to the experts.
The fritillary, held for the photo by a friend
The answer took some time to arrive but eventually it did: Fritillaria affinis it is! So no groundbreaking discovery here, but still a nice variant with some interesting features similar to a more southern species.
Further down Deep Gulch Trail the trees were less dense and patches of sunshine lit other beautiful flowers. Closer to the end of February there were quite a few violets in the sunny spots.
Golden Violet (Viola douglasii)
And further down a few larkspurs stood out in velvety-blue. I was happy to see them.
Zigzag Larkspur (Delphinium patens)
In his book, Quicksilver: The Complete History of Santa Clara County's New Almaden Mine, Jimmie Schneider tells that Deep Gulch used to be the dump of the local homestead until one big storm had delivered justice and washed all the junk down the creek, depositing it back in the neighborhood's yards.
Lomatium sp.
For several decades after the New Almaden Mining Company had closed its business mercury was still being mined in New Almaden by small time miners with little assistance and limited scale equipment. Mercury was still being purchased for various uses such as thermometers and liquid switches and such. Eventually even these efforts have dwindled. There is still plenty of good scale cinnabar inside that hill but it is no longer profitable to mine it. With the heightened public awareness of mercury's toxicity, even the last attempt in the early 1970 to revive larger scale mining had failed and the mine closed for good.
Manroot bine
The New Almaden area was parceled and put for sale but was saved in the last minute by local activists who convinced Santa Clara County to purchase the area and make it into a park.
New Almaden is big. The loop I hiked is just the tip of what this magnificent park has to offer. The trails are well maintained and well marked and hiking there is an absolutely lovely experience of both Nature and history. I totally recommend to visit this park.
The twisted rock at the bottom of Deep Gulch
On Old Almaden Road, just before the Mine Hill staging area there is a big, white mansion called Casa Grande. In the Mining days this used to be the company's manager home. Now it is a museum and a visitor center. There are very interesting exhibits there and I recommend stopping there on your way in or out of the park. The rangers also take people on free history tours in the park - check out the schedule at the Santa Clara County Parks website.

Many thanks to members of the California Native Plants Society and the naturalists of Santa Clara County Parks for their help in identifying the fritillary!


  1. Very nice and interesting trail.

    The quartz formation reminded me a koala bear - to match the eucalyptus :-)

    "Thing"is a very good name for the branch.

    I'm amazed by your dedication going to bring the coordinates...

    1. I couldn't go back on my word now, could I? My honor was on the line ...
      And I am pretty sure I was inspired by the same 'Thing' you think of :-)

  2. Replies
    1. I might have shot those same mushroom clouds--March 1 (along the Los Gatos Creek Trail in Campbell). https://www.facebook.com/photo.php?fbid=10205651529902832&l=f5e68b0ed0

    2. (Sorry that doesn't come thru as a clickable link. Just my photo.)

    3. That is so cool! I saw your photo, and happy to find out that I'm not the only one who was inspired by them :-) Thanks for sharing!

  3. Thank you again.
    I enjoyed the beautiful place with you.

    1. Thank you my friend! I'd love to show it to you in person :-)

  4. so lovely, the newts and all the flowers :-)
    is it an american custom to leave cars in abandoned trails? I remember the one from death valley... ;-)
    the veronica persica is extremely rare here, and for you its invasive...

    1. I don't think so. It used to be a private property and it might be that the parks agency didn't want to deal with the cars' removal (they had to deal with removing a lot of toxic waste). Anyway, it adds to the historic appeal of this place, I think.