1906 – U.S. Geological Survey – Topography Map – Description & Symbols
New Jersey – Pennsylvania – Lambertville Quadrangle
Edition of July 1906; Scale 1/62500
Back side of map: Description of the map, Conventional Signs (symbols)
Tag – HwTwp
File – 1906-HwTwp-USGS-NJ-Topo-Lambertville-USGS-Symbols.jpg
