A Long History in the

Santa Ynez Valley

A group of nine people standing side by side outdoors in front of a large industrial mining structure, with some of them wearing casual clothing and some in shirts and pants, under a cloudy sky.

From Riverbed to Legacy— Since 1939

What began as a discovery in the Santa Ynez Valley became a multi-generational operation rooted in land, labor, and community. Buellflat has been operating since the 1930’s under H. George Petersen & Sons, producing sand and aggregates from materials sourced from the Santa Ynez River using crushers and screening systems.

Over the decades the operation expanded while maintaining its commitment to quality materials and reliable service.

1940s — First Operations

In 1939, the land along the Santa Ynez River revealed something valuable.

Beneath the surface was a natural supply of sand and aggregate — materials that would go on to support the growth of roads, homes, and infrastructure across the Central Coast.

What started as a local operation quickly became something more. The founders recognized not just the resource, but the responsibility that came with it — to produce quality materials and serve a growing community.

This was the beginning of Buellflat Rock.

Black and white image of roller coaster tracks rising into the sky with mountains in the background.
A vintage black-and-white photo showcasing three men standing in front of a large firefighting truck with a ladder on top. The men are dressed in casual and work attire. The truck has signage on the side indicating it belongs to the Fire Department.

Buellflat Rock operations, early years

Black and white photograph from September 1963 showing machinery at the Buell Flat Rock quarry, including a conveyor system, a bulldozer, and construction workers operating equipment.
Black and white photograph of a Caterpillar 944 loader moving sand into a bucket at a processing site with an overhead conveyor system in the background.

As demand grew, Buellflat Rock expanded its operations with crushers, screens, and conveyor systems.

By the early 1960s, the site had developed into a full aggregate processing operation — producing consistent, high quality materials at scale.

Equipment like loaders and conveyor belts transformed how materials moved through the site.

1950s–60s — Building the Plant

1960s — Regional Impact

Materials from Buellflat Rock were used across the Central Coast as infrastructure and development expanded.

Sand and aggregate sourced from the Santa Ynez Valley became part of roads, foundations, and projects that shaped the region.

The operation became a trusted local supplier.

Black and white industrial mining structure with stairs and conveyer belts.
Construction workers loading a dump truck with wooden planks on a sunny day.
Two dump trucks driving along a construction site with a building framework in progress and a dirt road. Handwritten notes at the bottom indicate date and location.

A Family Legacy Continues

As the business grew, the next generation stepped in — continuing the work and expanding the operation.

The knowledge of the land, materials, and process was passed down, preserving both the craft and the responsibility of the operation.

Buellflat Rock became a multi-generational business rooted in consistency and trust.

Over time, the operation expanded across what is now approximately 200 acres in the Santa Ynez Valley.

The site evolved to include material processing, equipment operations, and additional infrastructure supporting production and storage.

This growth allowed Buellflat Rock to serve a wider region and larger demand.

Next Generation

Today— Active Production

Operating Today

Today, Buellflat Rock continues active aggregate production through deep mining and a processing plant fed by loaders.

Materials are screened and processed to deliver consistent, high quality sand, gravel, and rock products for construction and landscaping.

The operation serves customers across the Tri County region and beyond.