REDBALL Magnetic Anomaly Map: Ticonderoga 15' quadrangle. 1:62,500 scale. (see also 4b021 and 4b291). Data collected from areomagnetic and ground surveys, late 1940s.
REDBALL Magnetic Anomaly Map: Ticonderoga 15' quadrangle. 1:62,500 scale. (see also 4b021 and 4b291). Data collected from areomagnetic and ground surveys, late 1940s.