History of Empire Mine

A high-risk history of vision, innovation and old-fashioned hard work

Empire Mine’s history began in 1850 when George Roberts found hard-rock gold in a quartz vein – more than a year after James Marshall discovered placer gold at Sutter’s Sawmill.   Suddenly, Northern California was a magnet for those seeking wealth, new opportunities, and adventure.   People from all walks of life and from all over the world flocked here for a piece of the action.

In 1851, Roberts sold his interest, and by 1869, new owner, San Francisco entrepreneur William Bowers Bourn, Sr., held the controlling interest.   The Bourn Family retained ownership until 1929 when Empire Mine was purchased by the Newmont Mining Company for $250,000. Operations ceased in 1956.  The stamp mills that once thundered 24 hours a day were silent, and its glory days became a memory.  In its heydays, Empire Mine produced 5.8 million ounces of gold, and it ranked as one of the largest, oldest and most prosperous mines in North American history.

Its purchase in 1975 by the State of California marked a new beginning for the historic site.  Today it continues to lure visitors from all over the United States and all over the world.  Empire Mine State Historic Park welcomes around 100,000 a year, as they discover what life was like in those days of gold, grit and glory.  Its tours of Empire Cottage (the Bourns’ summer home), the Clubhouse, the gardens and the Mine Yard are fascinating.  The Living History Programs, both in the Cottage and the Mine Yard, bring the past to life in a convincing, memorable way.  Today the mine is almost completely filled with water , however visitors can still look down the mine shaft portal to the 150-foot level.  Empire Mine’s close to 850 acres are rich in history and beauty.  At elevations of 2,500 to 2,900 feet, they cover a maze of 367 miles of deep mine shafts.   Located in the western Sierra Nevada, 50 miles from Sacramento, Empire Mine State Historic Park remains rich in gold-mine history.

Key dates in Empire Mine’s unique history


William Bowers Bourn, Sr. purchased controlling interest of Empire Mine


The shaft at Empire Mine reached down to the 1,250 foot level, with 7,900 feet of drifts


William Bowers Bourn, Sr. died in San Francisco


William Bowers Bourn, Jr. went to England to attended Cambridge University


William Bourn, Jr. formed the Original Empire Mill and Mining Company


Bowers’ cousin, George Starr, began working at Empire as a mucker


William Bourn, Jr. formed the Grass Valley Water Company to bring water to theEmpire and North Star Mines


The main power source was changed from steam to water, using Pelton


George Starr installed compressed air-powered drills for development work


George Starr moved to South Africa to supervise a gold mine


Famous San Francisco architect Willis Polk designed and constructed Empire Cottage and the grounds for the Bourns


George Starr returned to Empire as mine superintendant


Mules were introduced to the mine


Katy Moriarty arrived to be the housekeeper at Empire Cottage


George Starr’s reconstruction of the mine was completed, and reached depths exceeding the 3,000 foot level


Willis Polk designed and constructed the prestigious Clubhouse


William Bourn, Jr. sold Empire Mine to Newmont Mining Company for $250,000


The stamp mill at Empire was increased to 80 stamps


The greatest depth on the incline was achieved in the North Star shaft at 11,007 feet


Newmont held an auction to sell the contents of many of the buildings and materials


The State of California purchased the surface property of the Empire Mine from Newmont Mining Company for $1,250,000

Mining Methods

Traditional placer mining methods that depended on using water to wash gold deposits from the sand or gravel of stream beds did not work in the Grass Valley area.  Instead, miners used “hard-rock” mining methods.  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.

At the stamp mill, the crushed ore, mixed with water, was washed cross copper plates coated with mercury.  The mercury 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, Empire adopted a more efficient mining method.  In this process, cyanide was used to dissolve gold while it was 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.


Until mules were introduced, miners moved the ore-laden cars manually.  Known as one of the most efficient gold mines in the U.S., Empire counted the use of mules to pull ore cars as one of its greatest innovations.  The mules lived in underground stables until they became too old to work.


Empire Mine did not begin to prosper until 1869, when William Bowers Bourn, Sr. acquired the controlling interest.  Production dropped in 1874, followed by Mr. Bourn’s sudden death that same year.

William Bowers Bourn, Jr.

In 1879, 22-year-old William Bowers Bourn, Jr., took over management of the mine to keep it from closing.  Fortunately, he was able to bring the mine back to profit.  He was later able to push several mine shafts past the 1,200-foot level that had been considered the maximum depth.

He commissioned famed San Francisco architect Willis Polk (who had designed the Bourns’ Webster Street mansion in San Francisco) to design the mine managers’ complex, Empire Cottage, the magnificent gardens, and the Clubhouse, where the Bourns entertained their prestigious guests.

George W. Starr

William Bourn, Jr. had a talented, 19-year-old cousin named George W. Starr who began working at the mine in 1881.  He started his career at a mucker, loading rocks and ore into cars.  By 1887, he was the mine’s superintendent.  In 1893, Starr, considered to be a mining genius, left to work in South Africa’s gold mines.  When Starr visited San Francisco a few years later, Bourn convinced him to return to Empire Mine, where Starr remained for another 30 years.


Agnes Moody Bourn

In 1881 William married Agnes Moody in New York.  The Bourn and Moody families were friends. Mrs. Bourn was actively involved in the development of the grounds and rose gardens at Empire Cottage. She and Mr. Bourn were patrons of the San Francisco Symphony and Operas. They often entertained friends and acquaintances by having famous musicians play in their homes.  Mrs. Bourn played the piano. She and Mr. Bourn had one daughter, Maud.

Libby Starr

Born in New York State in 1866, she married Empire Mine’s superintendent, George Starr in 1886.  The Starrs had two children, William and Dorothy.  Libby played an active role in the Grass Valley community, and in 1915, she and close friend Grace Clinch formed the Empire Country Club.  Members met for games, dining and dancing in the stately clubhouse.

Katy Moriarty

Born in Ohio in 1865, Katy moved to California in 1888 with her brother and sister.  She worked as a housekeeper in the Bourns’ prestigious San Francisco home on Webster Street.  In 1900 she went to Empire Cottage in Grass Valley where she served as caretaker and housekeeper until she retired in 1934. She was reputed to have run the Cottage like clockwork – and often supplied the local orphanage with home-baked cookies.

End of a golden era

Empire Mine closed during World War 11 when many miners enlisted.  In 1945 the mine reopened, but gold remained at its 1934 price of $35 per troy ounce.  Unfortunately, it cost more to bring the gold to the surface than it was worth.  However, mining efforts continued for another decade.  In 1956, when its doors closed forever, it had produced nearly six million troy ounces of gold – a true bonanza!


Gold deposits of the Grass Valley mining district occur in quartz veins, deep underground.  Granite bodies called plutons were formed when molten rock (magma) slowly cooled below the surface of the earth.  During the final stages of cooling, liquids with dissolved silica and gold pushed their 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.

Related places of interest

The Filoli Mansion, Woodside, California

Following San Francisco’s catastrophic 1906 earthquake and fire, the Bourns built their magnificent 43-room mansion, Filoli (an acronym for Fight, Love, Live) in Woodside, 30 miles south of San Francisco.  With its famous gardens on 600 acres, you can read about Filoli here.

The Muckross House, County Kerry, Ireland

William Bowers Bourn, Jr. and his wife, Sarah, had only one child, Maud.  Maud married Arthur Rose Vincent of County Clare, Ireland.  Her father purchased the magnificent Muckross property in Killarney, County Kerry, as a wedding present.   Today Muckross House, Gardens and Traditional Farms is a National Park.  You can read about Muckross House here.

Recommended reading

These fascinating, historic accounts of our gold-mine history are sold in our Gift Shop.

  • Tears From the Sun A Story of Gold video-Stanley H. Halls
  • Hydraulic Gold Mining video-California State Parks
  • Hard Rock Gold Mining video-California State Parks
  • What’s So Great About Granite?-Jennifer H. Miller
  • Rocks & Minerals Facts at Your Fingertips-Pocket Genius
  • Rocks, Fossils, & Arrowheads-Laura Evert
  • California Rocks! A Guide to Geologic Sites in the Golden State-Katherine J. Baylor
  • California Underground adventures-Jon Kramer & Julie Martinez
  • Geologic Trips-Ted Konigsmark
  • The Gold Rush-Bobbie Kalman
  • Dig Into Rocks Minerals & Crystals-GeoCentral Children’s book
  • Life of a Minor-Bobbie Kalman
  • The Blacksmith-Bobbie Kalman
  • History of the Empire Mine-Charles A.Bohakel
  • Local History Makes Good News!-Robert M. Wyckoff
  • Hiking the Sierra Nevada-Barry Parr
  • Discover California Gold! Country-coloring book
  • California Geography The Golden State-Randy L. Womack, M. Ed.
  • California Atlas-California Geography Associates
  • The Cyanide Plant More Gold from the Same Ore-Roger P. Lescohier
  • Lester Pelton & the Pelton Water Wheel-Roger P. Lescohier
  • The Stamp Mill for Recovery of Gold from Hard Rock-Roger P. Lescohier
  • The Cornish Pump in the California Gold Mines-Roger P. Lescohier
  • Gold: The Saga of the Empire Mine 1850-1956-F.W. McQuiston, Jr.
  • Gold Giants of Grass Valley-Roger Lescohier
  • The River-Hank Meals
  • Walking Tours & twice-told Tales of Grass Valley-Robert M. Wyckoff
  • Sierra Stories-Gary Noy
  • Ghost Hunter’s Guide to California’s Gold Rush Country-Jeff Dwyer
  • Where to Find Gold in Northern California-James Klein
  • Exploring Nevada County-Nevada County Historical Landmarks Commission
  • Images of America Gold Rush Towns of Nevada County-Maria E. Browser
  • Images of America Grass Valley-Claudine Chalmers
  • The Bourn Dynasty-Charles C. Steinfeld
  • Soiled Doves Prostitution In The Early West-Anne Seagraves
  • With Great Hope women of California Gold Rush-JoAnn Chartier & Chris Enss
  • The Shirley Letters-Louise Amelia Knapp Smith Clappe
  • Highly Respectable Families-Shirley Ewart with Harold T. George
  • Last Bonanza Kings The Bourns of San Francisco-Ferol Egan
  • The World Rushed In-J.S. Holliday
  • The Golden Corridor-Jody & Ric Horner
  • The Golden Highway 49, Vol 1 North-Jody & Ric Horner

© Empire Mine Park Association