Keysight Technologies has confirmed thousands of important papers related to Silicon Valley's early history it stored in Santa Rosa were destroyed in the North Bay fires.

The archives, which contained about 100 banker's-sized boxes of the writings, speeches and other materials by Silicon Valley pioneers David Packard and William Hewlett, were windows into their thinking and dated as far back as 1937, according to former archivist Karen Lewis, who assembled the collection for Hewlett-Packard Co. beginning in 1987.

Lewis, who was the Harvard University archivist prior to being hired to care for the HP archive, said the collections contained the history of Silicon Valley. The documents were the record of California's "second Gold Rush."

"It was a very exciting and wonderful collection. It's a huge, huge loss," she said.

The papers burned on Oct. 9 when modular buildings at Keysight's Santa Rosa headquarters were destroyed in the Tubbs Fire, Keysight said in a statement on Monday. Keysight previously declined comment on the loss on Oct. 13, citing a need to focus on finding and helping employees who had lost their homes in the tragedy.

The papers, which dated from 1937 to 1995, documented the evolution of technology globally and provided a road map to how Packard and Hewlett conceived building Silicon Valley. They discussed how little California companies would be able to crack into sales to the federal government and how they developed their business model, which has become the cornerstone for Silicon Valley companies throughout the region today, she said. The discussions led to forming the West Coast Electronic Manufacturers Association in 1943, a nonprofit technology trade association that later changed names and merged with Information Technology Association of America to become TechAmerica.

Lewis said the papers also highlighted Packard's enlightened management techniques by using teams of people to inspire each other rather than work under a top-down approach, and Hewlett's ideas about technology, which remain fundamental to Silicon Valley.

"They had the most amazing partnership," she said of what the archives revealed. "Dave's brilliance was in the management of ideas and people; Hewlett was prescient about what kinds of technology people would want and need," she said. And what impressed her most was how they worked together so well for so many years. "They could step into each other's shoes and often did," she added.

Brad Whitworth, a former HP international affairs manager who also oversaw the archives until 2003, said they contained invaluable materials, including oral histories and speeches.

"In some ways, this was the paper version of the HP garage at 367 Addison Ave. It is like a presidential library losing all of its speeches and correspondence or ... Henry Ford's building laboratories. For Silicon Valley, it had that kind of value," he said.

Keysight did not say what the loss was in dollars. The company is still evaluating the loss. But Lewis said the damaged archives, which were mostly composed of letters, speeches, oral histories and other correspondence by Hewlett and Packard were valued at about $2 million based on a 2005 appraisal done for Agilent, which valued the entire archives at $3.3 million. Photographs, technical drawings, early Hewlett-Packard Journal magazines and early hardware rounded out the balance at about $1 million.

Lewis said the appraiser found the collection was one of the most historically significant company archives remaining outside of nonprofit institutions. "Interest in this archive would only increase with the passage of time," she noted the appraiser had said.

Whitworth noted that some of the archival materials stored 200 yards away in Keysight's glass, concrete and metal buildings were not damaged.

But because the papers were deposited in modular buildings, "they were toast," Lewis said.

The archives were originally stored in a special facility at HP's headquarters at 3000 Hanover St. in Palo Alto, where they were kept under lock and key in a vault inside the visitor's center. The facility had a no-water-based fire-retardant system, humidity controls and ultraviolet light protection, Lewis and Whitworth said.

When HP created Agilent Technologies in 1999 to spin off its electronic measurement work, the archives were moved to Agilent's nonprofit foundation, where they were kept in a similar environment. When Agilent split off a separate electronic-measurement company, Keysight, in 2013 and 2014, the archives were stored at Iron Mountain, a company that stores and protects archival information. By 2014 they were moved to Keysight.

Lewis said her first choice was for the archives to go to Stanford University, where Hewlett and Packard both graduated. An academic institution would also have experience and facilities for properly housing the archives.

Keysight acknowledged that a number of historic items were undamaged because they were situated in other parts of the Santa Rosa facility, which sustained only minor damage. Other company archival materials, such as historic products (hardware), product catalogs and manuals, some correspondence by David Packard and other company research collections were also unaffected because they are housed at other Keysight locations. Some archives had been previously saved digitally and also were unaffected by the fire.

The company also disputed claims that it had not adequately protected the papers.

"Keysight met and exceeded the strictest standards for archival protection, including guidelines set by the United Nations and the Library of Congress. The archives were stored on metal shelving in archival quality folders inside damage-resistant archival boxes in a secure building with a sprinkler system at the company's Santa Rosa headquarters -- standard practice for archival collections -- and in the same way the archives were stored when they were located previously at the Hewlett-Packard and Agilent facilities. According to the Smithsonian Institute, an automatic sprinkler system is the single most important fire-safety system a cultural property can have," the company said in a statement.

"It took the most damaging fire in state history to thwart the appropriate and responsible steps we took to protect our company archives. The heat from the Tubbs Fire was so intense that many fire-resistant safes were melted and destroyed in this unprecedented firestorm."

Lewis said that some of the archives survived -- in particular many photographs -- because the images were converted digitally, but digital conversion of the many papers was not possible for a number of reasons. Many were thin carbon-paper copies kept by secretaries and would not have reproduced well by optical character recognition software; others were on fragile papers that could not easily be scanned or microfilmed; and there was never the budget to scan all of the work, she said.

Whitworth said that in some ways they are back to where they started, with a need to catalog whatever remains and wherever it is stored. Parts of the collection are housed in different locations, not only at Keysight.

"I hope whatever is left, that they make sure it is extraordinarily protected," he said.

To view the archives online, including many historical photos, go to history.keysight.com.