- Written by Mark Kuhar
March 10, 2013 – They are dreaming in California if they think they have enough aggregates reserves. Despite several approved and extended rock mines in the last 10 years, Fresno County, Calif.'s current aggregate reserves are not expected to last very long, according to a recent report by the state Department of Conservation. The raw material required to make ready-mix concrete, asphalt, road base and a wide variety of other building products, aggregate is still in short supply in the Valley, the latest California Geological Survey shows. In the Fresno production-consumption (P-C) region, which includes both Fresno and Madera counties, there are 46 million tons of permitted aggregate reserves, less than 11 percent of the 50-year demand of 435 million tons. Read the full story here.