Stone for the First Presbyterian Church of San Luis Obispo, Carnegie Library/History Center, and several retaining walls all originally were blasted off Bishop Peak. The rich, dark gray rock was a popular San Luis Obispo building material in the early 20th century.
The 1897 book “Railway Age Volume 24” says that the Pacific Coast Railway had completed a 3.7-mile spur to Bishop’s Peak.
The spur included a clever steam-powered cable drum that would lower a rock-filled car and lift an empty car up the hillside railway.
According to the website Quarries and Beyond, several of the volcanic sister peaks have been quarried. Cerro Romauldo was the site of the Lee Quarry. Morro Rock and Bishop’s Peak were all harvested for rock.
Bishop’s had two quarries operating.
The rock from one quarry was described as Andesite-granophyre (fine-grained volcanic rock often containing crystals) of dark gray color and subconchoidal (smooth shell-shaped) fracture. The other quarry harvested whole boulders.
According to the book “The Pacific Coast Railway” by Kenneth Westcott and Curtiss Johnson, the quarry spur line was closed by 1908.
The narrow gauge Pacific Coast Railway was gone by World War II.
Climbing websites warn today that the quarry is on private property and off limits. On Sep. 16, 1983, Telegram-Tribune reporter Alan Mittelstaedt wrote about the lost quarry:
SLO mystery railroad spurs him on
A huge chunk of Bishop Peak in San Luis Obispo is missing.
It vanished during a turn-of-the-century quarry operation that ripped thousands of tons of granite from the peak.
The mystery of the missing stones may not rival the enigma of the Egyptian pyramids, but more questions than answers remain about the operation.
At least for Mike Burrell, an Atascadero Junior High School history teacher who spent his summer vacation piecing together the fragmented past of the quarry operation.
“This (story) is something you better get now or it will be gone in 15 years,” Burrell said, referring to the few clues left to guide his exploration.
The few rusty narrow-gauge rails, some remnants of buildings and a huge rock pile are the only hints of the once-flourishing quarry atop Bishop Peak.
Armed with musty photos and stale-smelling maps, Burrell retraced the route of the narrow-gauge railway that in its heyday wound up Bishop Peak to the grayish rocks. He walked, camera in hand, where 80 years ago a narrow-gauge train had trudged up the mountainside.
The spur broke off from the main line of the Pacific Coast Railway line near Laguna Lake, wound around what is now This Old House restaurant on Foothill Boulevard and began the mile-long ascent to the mine.
The bustling mining activity of old has surrendered to the swallows and thistle-strewn grasses.
Hidden in the quiet scenery Burrell found the foundation of the gravity drum house, which used to pull empty box cars up the steep grade. He saw an old boiler stashed in a grove of sycamore trees. He also found remnants of a blacksmith shop and powder house, where explosives for the quarry were stored.
Burrell figures the significance of all that he saw is slowly creeping from the public consciousness.
He himself came late to consider the importance of the railway. In 1970, as a student at Cal Poly, Burrell first learned about the Pacific Coast Railway. Later, studying it more, he heard of the spur up Bishop Peak.
But the man who could have told him the most about the railway, Vincente Canet, died a couple years ago before Burrell could interview him.
“He was a human gold mine for information.”
When the operation closed down, or exactly how it worked, is unknown to Burrell. What isn’t a puzzle is the value of tracking such developments that had such a great impact on San Luis Obispo.
“I have a real desire to make history relate to the present,” Burrell said. “You can make up all these good stories about how, if you studied history, you avoid making mistakes. All that is nice, but I don’t believe it.”
Granite from Bishop Peak built the San Luis Obispo Presbyterian Church on Marsh Street, the old senior high school where Safeway [southwest corner of Marsh and Johnson streets] and the county Historical Society building, originally the Carnegie Library. The busy quarry closed down sometime before 1910 because of pressure from the area’s forerunners of the environmental movement.
The dynamiting shifted to Morro Rock, where scars of the mining operation are still visible today.
“To me, they were thinking so much of the local community, they didn’t mind blowing up Morro Rock,” Burrell said.
Burrell, back in the classroom, hasn’t given up the search for answers and someday hopes to write a pamphlet on the little known spur of the Pacific Coast Railway.
His exploring spirit doesn’t derive from any great love for the railroad. “I’m not a railroad buff. I just want to get it before it disappears.”