building the Oroville Dam

Oroville Dam – one of the greatest water projects in California history, was completed in May 1968. It is the keystone of California’s $2.2 billion State Water Project, built in the 60s and 70s to provide water for arid Southern California. Oroville began in 1957 with the relocation of U.S. Hwy 40 and the Western Pacific RR which both ran right through the future reservoir’s lakebed.

Oroville Dam was where Peterson cut its teeth on in combining traditional product support with innovative custom fabrication. Five years earlier (1957) Peterson had been awarded the northern territory belonging to Sierra Tractor because Caterpillar felt Peterson was better equipped to handle the large-scale water projects than the local ag-dominant dealer. Trinity Dam was followed by Whiskeytown Dam (both near Redding) and in 1962, the mammoth Oroville Dam construction officially began.

The job veered away from conventional construction methods when the bid winner – Oman Construction out of Nashville – decided to transport fill materials using a railroad system rather than trucks and scrapers. “We were gambling on some of our contractors getting Oroville Dam,” recalls Howard Peterson. “We went to the bid opening in Sacramento and an unheard-of, out-of-state contractor, was low bidder. We were sick.” Howard and Buster immediately flew back to Nashville to meet Bill Oman. “We had a very warm reception. He took us into his home and practically treated us like sons.” Two days later, Howard left Tennessee with a large machine order and the beginnings of a promising work relationship with Oroville’s lead contractor.

Peterson fine-tuned its large fleet product support system, begun at Trinity, by providing a fully stocked, onsite parts trailer that was serviced daily from the new Chico store. Resident mechanics and round-the-clock service were also part of the package, along with a 60-piece order of new machines and rental equipment, which included: ten D9s, some D8s and compactors, 20 bottom-dump wagons powered by 660 tractors, four 660 scrapers, some 988 wheel loaders, a couple No. 16 motor graders and six rental DW20 (pull-scrapers). Everything used on that job was CAT, if CAT made it at the time.

The scope and difficulty of the project really put Peterson to the test in terms of whether to supply the traditional means or really step up and be progressive and offer new solutions to head-scratching problems. According to Western Construction magazine’s October 1966 issue, “Buster’s Quad D9s were the star of the show on the $20 million spillway. Excavation of some 4 million cubic yards of solid rock made it one of the biggest ripping jobs in the West at the time. One million yards of that material had to be ripped using various methods, including Peterson’s new Quad D9 arrangement, outfitted with two 10-ft shanks, each with 4-ft extensions. The rock was so hard that when points and shanks wore out, they simply replaced rather than rebuilt them. Also new on the dam portion of the project was CAT’s new hydraulic 660 tractors pulling Buster’s 97-ton Athey rock wagons [patent # 3185528] designed especially with hydraulic actuating hopper doors for Oroville”.

Along with new equipment innovations, Peterson made heavy use of its parts drop system, begun at Trinity Dam to expedite the heavy parts demands. Oroville was the main reason for bringing the nightly shuttle truck up north, according to retired shuttle truck driver, Fred Knowles who clocked over 3 million miles on the road for Peterson.

Today, Oroville still stands as the tallest earth-fill dam in the United States and among the top 20 in the world. The job was considered the most highly automated of its kind in the 1960s, involving an astounding volume and variety of equipment, much of it specially designed. Aside from the traditional CAT equipment used on the job, Oman employed several of Buster's innovations including the Quad D9s, the Athey bottom-dumps and the tandem 631 compactor.

BIG Magazine stated that, “if the material for the dam was moved by wheelbarrows, placed end-to-end, they would extend to the moon and back. More than 1.5 million RR cars made the trip from the tailing dump to the dam – enough to circle the globe at the equator, several times. The RR handled more than 300 million gross tons, more than several of the nation’s largest commercial railroads combined.” In other words, Oroville was, and still is, considered one of the construction marvels of the heavy construction industry.


For borrow, Oman used dredge tailings left over from turn-of-the-century gold mining operations, 14 miles away.

By early 1968, the 748-ft high dam wall was complete, making it the highest earth-fill dam in the nation. Eighty million cubic yards of material had been moved, from start to finish, with a total price tag of $439 million.

By May 1968, the 3.5 million acre-foot reservoir was filled and ready for dedication by Governor Ronald Reagan