Blue Diamond Materials

Bouquet Canyon Rock Company

California Department of Transportation

California State Lands Commission

California Portland Cement Company

CalMat Company

Catellus Development Corporation

CEMEX USA

The Dutra Group

Elementis Specialties.

Golder Associates, Inc.

Gold Fields Operating Company.

Greiner Engineering

Gresham, Savage, Nolan, & Tilden

Granite Construction, Inc.

Gypsum Resources, Inc.

Hanson Materials

Herron Construction

Hester's Granite Quarry

Hi-Grade Materials

Holcim Cement

James Hardie Building Products

Juniper Rock Quarry

Kern Rock Company

Kaiser Ventures

Lehigh Cement

Lilburn Corporation

Lytle Development Company

MCA of America

MK Gold Company

Mine Reclamation Corporation

Mitsubishi Cement Corporation

National Cement, Inc

Nevada Ready Mix

Phoenix National Petroleum, Inc.

P.W. Gillibrand Company

Riverside Cement Company

Sacramento County Planning Department

San Bernardino County Flood Control District

San Juan Gold Company

Santa Fe Mining, Inc.

Service Rock Products

South Coast Asphalt Products

Southdown, Inc./Cemex, Inc.

Specialty Minerals, Inc.

Strategic Development

Sunwest Materials\Teledyne Tungsten

Taylor and Wylie LLC

The Earth Technology Corporation

The Irvine Company

U.S. Borax

U.S. Bureau of Indian Affairs

U.S. Department of Defense

U.S. Department of Energy

U.S. Navy Department

Vulcan Materials

Woodward-Clyde Consultants