Purchased in 1971, the Leesburg Plant is located on Route 659, two miles south of Route 7. Leesburg has played a major part in supporting the development of Northern Virginia, especially areas west of Interstate 495. It has won numerous awards for environmental stewardship and community involvement, including a 2000 Platinum Environmental Eagle Award, 1999 Quarry of the Year (1st Place Runner up), and a 1997 Environmental Award. Leesburg has sponsored several educational programs, neighborhood associations, local youth sports teams, and fire/rescue squads.
Leesburg mines a type of rock known as traprock by miners or diabase by geologists – a dense, igneous rock with a greenish-black to bluish-black color. Formed by hot magma 200 million years ago, diabase is composed mainly of pyroxene, a dark mineral containing iron, and plagioclase, a lighter mineral in weight and color. Other minerals lending it its green-black color are epidote (green) and hornblende (black).