Maricopa Ready Mix | Scottsdale AZ – Manufactures more than 500,000 yards a year. The producer is a major player in the crowded Phoenix market, operating four ready-mix plants in the area. The company was originally founded with a shared ownership. Most of Maricopa was owned by concrete contractors, none of whom owned a stake larger than 20%. Today, the original owners are Maricopa board members, and the company has grown. Originally, the business plan was for Maricopa to make half of its sales to its own group of owners. Today, less than 25% of Maricopa’s sales are internal.