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