Thelen Sand & Gravel is a family owned corporation that offers a variety of aggregates, sand, decorative stones, boulders, recycled and specialty products to serve most any need. The company s sand is used in everything from the filling of children s sandboxes to 100,000-ton loads for applications in asphalt road bases, housing developments and construction sites. Thelen tests its materials to maintain quality control and meet the various American Society for Testing and Materials and State Department of Transportation specifications. Thelen Sand & Gravel maintains headquarters in Antioch, Ill.