Empire MineBrochure |
Brochure and Map of Empire Mine State Historic Park (SHP) in California. Published by California Department of Parks and Recreation.
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Our Mission
Empire Mine
State Historic Park
The mission of California State Parks is
to provide for the health, inspiration and
education of the people of California by helping
to preserve the state’s extraordinary biological
diversity, protecting its most valued natural and
cultural resources, and creating opportunities
for high-quality outdoor recreation.
Empire Mine State
Historic Park — site of one
of the largest, richest,
and longest-operating
(1850-1956) gold mines
in California — produced
more than eight billion
California State Parks supports equal access.
Prior to arrival, visitors with disabilities who
need assistance should contact the park at
(530) 273-8522. If you need this publication in an
alternate format, contact interp@parks.ca.gov.
dollars in gold
by today’s standards.
CALIFORNIA STATE PARKS
P.O. Box 942896
Sacramento, CA 94296-0001
For information call: (800) 777-0369
(916) 653-6995, outside the U.S.
711, TTY relay service
www.parks.ca.gov
Empire Mine State Historic Park
10791 East Empire Street
Grass Valley, CA 95945
(530) 273-8522
© 2012 California State Parks (Rev. 2016)
ca. 1898
E
mpire Mine State Historic Park
preserves what was once California’s
richest gold-producing mine. Located in
the western Sierra Nevada 50 miles from
Sacramento, this 856-acre park sits among
beautifully forested foothills at elevations
of 2,500 to 2,900 feet. Its 367 miles of deep
mine shafts form a maze that is impressive
to this day.
PaRK HISTORY
Native Americans
At least 10,000 years ago, the western Sierra
Nevada was populated by the Foothill
Nisenan. Their lands were made up of the
Yuba, American, and Bear River drainages
and parts of the Feather River.
The 1848 gold discovery brought tens of
thousands of fortune-seekers to California,
devastating the lives of the Nisenan. These
so-called “Forty-niners” took the lands that
the Nisenan had occupied for thousands of
Mine Manager’s Office
years and claimed it for mining, farming, and
logging. Many Nisenan died from exposure
to smallpox, measles, and other diseases to
which they had no immunity.
Today, Nisenan descendants live on and
near traditional tribal lands, teaching their
culture and language to a new generation.
New Mining Methods
In 1850, prospectors found gold-bearing
quartz in what is now Grass Valley.
Traditional placer-mining methods, in which
water was used to wash gold deposits from
the sand or gravel of stream beds, was
ineffective in this area. Instead, the miners
used “hardrock” mining methods, in which
men in buckets were lowered into deep
shafts (coyote holes) resembling water wells
to chip and drill through the rock. After
filling the drill holes with black powder, they
detonated it, loaded the blasted rock into
ore cars, and took it to the mine headframe
for primary crushing.
Assay Office
ca. 1890
At the stamp mill, the crushed ore, mixed
with water, was placed on copper plates
coated with mercury.
The mercury-coated copper combined
with “free” gold to form an amalgam. Water
washed away any impurities, and the
cleaned amalgam went to the refinery for
further processing.
In 1905 the Empire adopted a more
efficient mining method. In this process,
cyanide was used to dissolve gold while it
Refinery Room
until they became too old to work.
The Empire Mine did not begin
to prosper until 1869, after San
Francisco businessman William B.
Bourn, Sr., acquired a controlling
interest. Production dropped in
1874, followed by Mr. Bourn’s
sudden death that same year.
he had gone from loading rocks
and ore into cars (mucker) to
superintendent. In 1893 Starr—
by then considered a mining
genius — left to work in South
Modernization and Mules
Africa’s gold mines. When
Until mules were introduced, miners moved
Starr visited San Francisco
the ore-laden cars manually. Known as one
a few years later, Bourn
of the most efficiently operated gold mines
convinced him to return
William Bowers Bourn, Jr.
in the U.S., the Empire counted among its
to the Empire, where Starr
improvements the use of mules to pull ore
In 1879, Mr. Bourn’s 22-year-old
worked another 30 years.
cars. The mules lived in underground barns
son, William B. Bourn, Jr., took
After 1929 the Empire
over management
Mine — first combined with
of the mine to keep it
William Bourn, Jr.
the North Star Mine as Empirefrom closing. Fortunately,
Star Mines Ltd. and then sold to
he was able to lead the mine
Newmont Mining — produced enough gold
back to profit. He was later
to keep the Great Depression of the 1930s
able to push several mine
just a story in the local newspapers.
shafts past the 1,200-foot level
End of the Empire
that had been considered the
maximum depth.
The mine closed during World War II when
many miners enlisted. In 1945 the mine
George W. Starr
reopened, but gold was still at its 1934
Mr. Bourn’s 19-year-old cousin,
price — $35 per troy ounce. Unfortunately, it
George W. Starr, began work
then cost more to bring gold to the surface
at the mine in 1881. By 1887
than it was worth. However, mining efforts
continued for another decade. In 1956,
ca. 1870
The Cornishmen
when the Empire closed, it had yielded
Cornish miners, who arrived from Cornwall, England, around
nearly six million troy ounces of gold — a
the mid-1850s, brought with them a well-honed work ethic and
true bonanza.
1,000 years of history as hard rock miners. They also brought the
Geology
Cornish pump, which allowed them to pump water out of the
Gold deposits of the Grass Valley mining
1,200-foot mine shafts.
district occur in quartz veins deep under
When shafts were drilled below the earth’s water table,
ground. Granite bodies called plutons were
they would fill with water. Each Cornish pump could draw
formed when molten rock (magma) slowly
18,000 gallons of water per hour from the shafts, replacing
manual mud diggers. Between the late 1870s and 1956,
cooled below the surface of the earth.
when the mine closed, Cornishmen provided the bulk of the
During the final stages of cooling, liquids
mine’s labor force.
with dissolved silica and gold pushed their
Crystalline gold
was still embedded in the quartz. The gold
could then be leached out of the quartz ore
in a liquid form. The cyanide method is still
in use around the world.
from Empire’s Pennsylvania Mine
ca. 1940
way into the fractures, shear zones, and fault
lines of older rocks and hardened, forming
the solid veins of gold found in quartz.
These geologic actions, happening miles
below the surface of the ancestral Sierra
Nevada, were later uplifted and revealed by
tectonic movement.
ACCESSIBLE features
Due to historic doorway widths and steep
stepwells, not all exhibits and attractions
are accessible. To arrange for transportation,
to borrow wide-tire wheelchairs, or for
information on alternative entries or lifts,
ca. 1940
ask at the visitor center, call the park, or visit
http://access.parks.ca.gov.
Exhibits / Programs — The visitor center and
museum are generally accessible.
Parking / Restrooms — Parking on the south
side of Empire Street allows close and safe
access. Accessible restrooms are near the
south parking lot.
Mine shops and exhibits area — Routes
through the park include some paved
walkways, some sloping terrain, and shifting
gravel. Restrooms are generally accessible.
Empire Cottage — The first floor of the
cottage interior, generally accessible except
for one tight hallway, is shown by guided
tour only. Formal gardens may be seen from
above at the ramp to the cottage.
NEARBY STATE PARKS
• Malakoff Diggins State Historic Park
23579 North Bloomfield Park Road
Nevada City 95959 (530) 265-2740
• South Yuba River State Park
17660 Pleasant Valley Road
Penn Valley 95946 (530) 432-2546
PLEASE REMEMBER
• Stay on marked trails.
• To ensure public safety, some areas are
fenced and closed to the public.
• Drinking water and restrooms are not
available along the trails.
• Watch out for poison oak, ticks,
and rattlesnakes.
• Roads and trails allow dogs on a sixfoot leash only. Except for service
animals, dogs are not allowed inside
historic buildings or in mine shafts.
• All natural and cultural features are
protected by law and may not be
disturbed or removed.
ca. 1940
st
Em
St
ree
18
t
rk
Pa
Reflecting
Pool
Rowe
Headframe
Me m o r i a l
e
pir
Formal
Gardens
Empire Mine Cross Rd
Ea
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174
Ore Bin
Tr l
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e
p ir
Legend
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Major Road
Paved Road
Paved Path
16
Hiking Trail
Somerset Drive
Park
Entrance
Em
ast
e
Str
Multi-Use Trail
Garage
(Hike/Bike/Horse)
Historic Area
15
New Rich
Hill Shaft
Historic Building Site
1
2
3
4
6
5
Historic Building
Mine Equipment
Exhibit
7
EMPIRE MINE
HISTORIC AREA
Caretaker’s
Residence
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Stamp
Display
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100
25
200
50
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300 Feet
100 Meters
to site of
Cyanide
Plant
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11
Tool Sharpening
Shop
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Buildings and Sites
1. Visitor Center and Model Room
The former carriage and automobile house
is now the visitor center. Gold samples are
on display.
The sprawling scale model display of the
Empire-Star Mine complex dates back to
1938. The once-secret model was regularly
updated to reflect the growth of the mine.
2. Mining Engineer’s Office
After the 1929 merger with North Star Mine,
this office housed the new engineering staff
hired to plan and direct the mine’s growth.
3. Mine Manager’s Office
This restored 1898 office represents the
ownership periods of both William Bourn, Jr.
and the Newmont Mining Corporation.
12
13
Hoist
Cable
Structure
Accessible Feature
Horse Staging Area
Mine
Picnic Area
Transformer
28
0
Restroom0
Auxiliary
Hardrock Generator
Trail
Parking
Visitor Center
4. Assay Office
Values were assigned to each gold sample
here; it now serves as a rescue station.
5. Refinery Room
Mercury from the stamp mill was recycled,
and the remaining sponge-shaped gold
nuggets were cast into 89-pound bars
and taken to San Francisco’s U.S. Mint.
After the cyanide process was installed in
1910, additional furnaces more efficiently
recovered the gold and silver.
and from the mine. From the headframe’s
crusher, ore went to the stamp mill for
further processing.
6. Warehouse
Reconstructed by volunteers in 1989, this
former hay- and supply-storage area is now
a meeting and training facility.
12. Compressor Building
The compressors pumped air into the mine
to ventilate it, and to operate machinery.
7. Welding Shop Site
After the mine closed, the old metal shop,
where equipment had been fabricated and
repaired, was torn down and sold.
8. Machine Shop
By 1886, Pelton water wheels provided
energy to run operations and lights. The
leather belts and ceiling-mounted shafts
and wheels are still in place.
9. Shaft Viewing Area
The ore “skips” that moved the rock to
waiting ore cars sped through this portal at
600 and 1,200 feet a minute. The deepest
shaft is more than 5,000 vertical feet down.
10. Blacksmith Shop
In the early days, equipment — from door
hinges to pump covers and stamps — was
fabricated in the company shops.
11. Headframe Site
The mine’s headframe, demolished in 1969,
supported a track that carried men,
equipment, and rock to
Blacksmith Shop
13. Hoist House
Here, skilled hoistmen raised
and lowered men, supplies,
waste rock, and ore to and
from the various mine levels.
Garden and greenhouse
to distinguish it from Mr. Bourn’s
14. Stamp Mill Site
Little remains of this building.
Heirloom roses other homes. The main floor holds
the kitchen, service rooms, living
Early in the process, its eighty
room, dining room, and a reading room later
stamps smashed the raw ore, which was
used as a bedroom by Mr. Bourn, Jr. Four
then washed over mercury-coated tables to
bedrooms and two baths are on the second
capture the gold.
floor. The servants’ rooms and a bathroom
15. Empire Clubhouse
were located above the kitchen.
William Bourn, Jr. built the clubhouse for
18. Gardener’s House and Greenhouse
use by his supervisory personnel and as
The Bourns loved trees and flowers of all
a place to entertain visiting guests. The
kinds. The nearly 1,000 vintage rose bushes
1905 clubhouse is still used by the Empire
seen in the formal garden and on the
Country Club and for park special events.
landscaped grounds were cultivated in
16. Starr Home Site
their greenhouse.
Only the foundation of Ophir Cottage,
19. Cyanide Plant Site (1910)
George Starr’s home, remains. Flames
Earlier methods of recovering gold were
destroyed it on October 28, 1935, despite
replaced by adding sodium cyanide to
all efforts to save it.
crushed ore. The cyanide dissolved and
17. Empire Cottage
separated the gold from sulfides. This area
This English manor home, designed in 1897
is closed to the public.
by architect Willis Polk, was called a cottage
Headframe
Mine Shaft
Machine Shop
Orleans Stamp Mill Foundation —
This stamp mill was in operation until the
early 1900s.
Orleans Mine — Under the leadership
of William Bourn Jr. (and later the Newmont
Mining Corporation), this small claim was
absorbed by the Empire Mine.
Pennsylvania Mine — The Pennsylvania
Mine site is marked by the concrete
foundations of its compressor house.
W.Y.O.D. Mine — The “Work Your Own
Diggins” mine leased claims to miners.
Mule Corral — This old corral was home to
the mules before they were lowered into
the mine.
Sand Dam — This waste rock area was high
and strong enough to support a narrowgauge rail line across Little Wolf Creek.
walking trails
The Union Hill, Hardrock, and Osborn Hill
Loop trails wind through nearly a century of
hardrock mining history. To ensure public
safety, some areas of the park are fenced
and closed to the public.
Union Hill Trails
These one- to three-mile trails feature
wildflowers in spring.
Pipeline Trail — This trail led from the
Empire Mine to the Northstar powerhouse.
Indian Ridge Trail — This trail was once
used by the Nisenan/Maidu people.
Union Hill Trail — This trail loops westward
from the north Pipeline Trail to the edge of
the park next to the town of Grass Valley.
Hardrock Trail Area
This easy two-mile walk circles much of the
Empire’s “outback.”
Hardrock Trail — Along this road, trucks
moved waste rock. A wooden pedestrian
bridge crosses Little Wolf Creek.
Stamp Mill Foundation — On this site,
California’s first stamp mill crushed goldbearing quartz, treated it with mercury, and
turned it into almost pure gold.
Cyanide Plant Site (closed to visitors) —
Cyanide dissolved gold-bearing sulfides,
allowing the recovery of more gold.
Trail Fork (Osborn Hill Trails) — From here,
Osborn Hill Loop climbs upward, ending
near several abandoned mines.
Osborn Hill Loop Trail
This demanding segment of the Hardrock
Trail leads to some abandoned mine sites.
Prescott Hill Mine — To the left
of the mine’s shaft foundation is the
headframe foundation.
Betsy Mine — The hoist and pump works
of this mine were removed before 1900.
Conlon Mine — This mine, difficult to
keep drained, closed in 1908.
Daisy Hill Mine — Two piles of waste
rock mark the site of the small Daisy
Hill Mine.
This park is supported in part through the
nonprofit Empire Mine Park Association
10787 East Empire St.
Grass Valley, CA 95945
www.empiremine.org
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©2012 California State Parks (Rev. 2016)
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