Along the shores of the American River near downtown Folsom sits a tall, narrow brick building that provided a key to Sacramento’s industrialization at the end of the 19th century.
The historic Folsom Powerhouse is surrounded by a canal system and forebays that diverted river water to produce electricity. Inside the building a row of transformers line one wall next to the facility’s control switchboard, clad in Tennessee marble. On the other side sit four massive black generators, connected to four large gravity-fed turbines in the adjacent hall.
The turbine hall at the historic Folsom Powerhouse. Water from the American River was diverted into the facility's forebay, then fed by gravity into the turbines, which spun electric generators.Sarit Laschinsky/CapRadio
The Powerhouse is one of the first examples of successful large-scale hydroelectric power in the country, and kept the lights on in Sacramento for over 50 years.
This year, the facility is celebrating its 130th anniversary.
An electrifying history
Construction on the Folsom Powerhouse began in the early 1890s, a time when hydropower was a new concept.
According to California State Parks, a limited number of electrical power plants had been developed over the previous decade in Germany and New York, but no project reached the size of the facility in Folsom.
Zakary “Zak” Adams is an interpreter with California State Parks. He told Insight Host Vicki Gonzalez the Folsom Powerhouse’s construction was the confluence of “a bunch of different conditions,” and that the facility was the “perfect site to pioneer this new kind of technology.”
“It’s a three [phase] 60 cycle power plant… when you drive under a power line, it’s the same kind of electricity,” he explained.
The Folsom Powerhouse first came online July 13, 1895. Electricity flowed through copper cables to the city of Sacramento 22 miles away, a first-of-its-kind achievement in the country.
Three of the four generators in the main powerhouse Aug. 16, 2025.Sarit Laschinsky/CapRadio
According to docent Daryl Walker, once that power got to the Capital City it was designated for very specific uses. “When they built the Powerhouse, they didn’t build it for residential, because there was no wiring in houses yet,” Walker explained.
“They got four customers online — the Southern Pacific Railroad maintenance yard in downtown Sacramento, Buffalo Brewery for an ice house, the electric trolley in downtown and a flour mill,” he said.
Walker said the power eventually spread to include street lights and the Capitol building, and later explained how this power helped grow both the regional and state economies.
In an email, he said the ice made in the brewery’s ice house was sold to farmers to keep their produce cold and fresh during shipping. “Prior to having the ice the farmers could not get their veggies/fruits to the East Coast without spoilage… needless to say the ice house opened the door for California farmers,” Walker wrote.
While the Powerhouse’s technology was cutting edge for its time, it was not without its dangers. Walker said he can recall at least one case of an employee being electrocuted in the facility. “You take a look at the control panel and how close your hands come to 800 volts, 529 amps… and back in the early days they weren’t even wearing rubber gloves or anything,” he said.
The marble control switchboard at the historic Folsom Powerhouse, Aug. 16, 2025. The facility produced 3,000 kilowatts, just 2% of the power generated by the modern Folsom Dam.Sarit Laschinsky/CapRadio
In another instance in 1901, one of the generators began speeding out of control. Attempts to slow it down failed and the generator tore itself apart, throwing pieces through the Powerhouse’s windows and embedding shrapnel in the ceiling that remains visible today. Fortunately, nobody was injured in the accident.
Shrapnel from Folsom Powerhouse generator #4 embedded in the ceiling of the facility. The generator came apart in 1901 after overspeeding.Sarit Laschinsky/CapRadio
Over time more powerhouses would come online to power Sacramento and the surrounding region, and the Folsom facility would send its last electricity in 1952. Walker said the Powerhouse’s original 90-foot dam on the American River had to be demolished for dredging operations to support the new Folsom Dam.
“Our little Powerhouse can only produce 2% what the big Folsom [Dam] can produce,” he said. “Technology had grown, it had served its time… time to move the next step up.”
Preservation and celebration
PG&E, the Folsom Powerhouse’s owners, donated the building to California State Parks in 1958 for preservation, which Adams said is a big part of the agency’s mission.
“You may think of a natural space, going to see a river or a canyon or mighty redwood trees… but we have lots of state historic parks across California that are meant to preserve historically significant buildings, structures,” he said. “We’re trying to protect these spaces so people can come and view them.”
Adams said staff and docents have worked hard to keep the facility’s original technology, dating back to 1895, in good condition. “Basically it’s as if they shut off the lights in 1952,” he said. “we kind of try to keep it in that space so you can come and see what that looks like…. at the advent of electricity here in California.”
Visitors to the state park will have a chance to view that original equipment Saturday during the 130th anniversary celebration from 10 a.m.-3 p.m. “You can check out the main powerhouse, we’ve got our lower powerhouse which is usually closed,” Adams explained, referring to a fifth generator and turbine installed in an adjacent building in 1897. The anniversary event will also feature cake, presentations, and the opening of several new exhibits.
The lower powerhouse is a separate building housing a fifth generator and turbine. It was added to the Folsom Powerhouse facility in 1897.Sarit Laschinsky/CapRadio
Adams said the date of the celebrations also comes with historical connections, specifically the Grand Electric Carnival of Sept. 9, 1895. While the Powerhouse itself came online on July 13, he said the workers needed time to work through teething troubles and increase the electricity supply to Sacramento.
“And so in September of that year… to celebrate the 45th anniversary of California being admitted to the Union, they lit up the Capitol Building in these big glowing arc lamps,” Adams said. According to California State Parks, the Grand Electric Carnival also featured a night parade of illuminated floats, pulled by electric streetcars, while the lit-up dome of the Capitol could be seen for 50 miles.
“They did this huge celebration where over 30,000 people came to Sacramento to celebrate this new technology,” Adams said. “This year, we’re going to be doing another celebration… 130 years of the Powerhouse, 175 for the State of California.”
Walker said he is looking forward to welcoming visitors to the Powerhouse and introducing them to the history that permeates the old building. “I enjoy people, I enjoy explaining how electricity is made… and I like when I see the light bulb come on in their head,” he said.
“It makes me feel good knowing I’m explaining something properly to somebody and they’re understanding it… that way they can really enjoy the overall concept of how the Powerhouse worked.”
You can hear more of the conversation, including about other features of Folsom Powerhouse State Historic Park and the Oct. 18 Electricity Fair, here.
