St. Thomas Development Company produces aggregates for highway, commercial and residential projects. The facility is easily accessible for your next project. Located on Old Lincoln Highway (Rte. 30), just west of I-81 and Chambersburg, PA, it is also just minutes from Maryland and West Virginia. The quarry offers a wide range of products, from stone dust to R-8 rip-rap material and DOT-certified limestone. Our high-calcium-content stone is ideal for cement production and power plant scrubbing material.