Located in Wrightsville, Pennsylvania, along the Susquehanna River, County Line Quarry was established in 1929 to provide construction aggregates to the surrounding areas of York and Lancaster counties.

County Line Quarry is a PennDot and AASHTO-approved source for quartzite phyllite crushed stone. County Line offers a wide range of sizes from manufactured sand to rip rap, with specialty aggregates also available. Some specialty items include DEP Sand, Non-Carbonic Landfill Stone, and SRL E-Rated asphalt aggregates for PennDOT hot mix asphalt projects.