Grimes Rock Plant

With more than 130 years of experience serving contractors, concrete producers, paving companies, and public agencies, CalPortland provides high-quality aggregates backed by technical expertise, reliable logistics, and sustainable resource management.

The Grimes Rock Plant is one of the largest construction aggregate processing plants in Ventura County. Located in Fillmore, California, we produce a wide range of materials that meet current Green Book and Caltrans specifications. Our sand and gravel blends are distributed throughout Ventura County, Santa Barbara County, and Los Angeles County, providing reliable supply for a variety of construction needs.

What you can expect from CalPortland:

• Proven Expertise – Decades of experience producing aggregates for everything from residential projects to major infrastructure and highway construction.
• Quality Assurance – Consistent gradation, rigorous testing, and compliance with ASTM and project-specific specifications.
• Technical Support – Knowledgeable materials specialists available to help with mix compatibility, performance needs, and project requirements.
• Reliable Supply & Logistics – Strategically located quarries, truck and barge distribution, and dependable inventory management.
• Broad Product Selection – Full lines of crushed stone, concrete sand, masonry sand, gravel, and specialty high-performance aggregates.
• Sustainable Materials Leadership – Pioneering recycled aggregate solutions to reduce waste and conserve natural resources.

Partnering with CalPortland means consistent, high-quality aggregates delivered with technical confidence and operational reliability.