Trinity Alps (CA)

Survey type M-Dz (magnetic; digitized from contour maps)
Flown by U.S. Geological Survey
Date flown 04/70
Line spacing 1.6 (km)
Altitude 2590 (m) by barometer measurement
Total distance 1,853 (km)
References
Counties Humboldt - Siskiyou - Trinity
Overlapping surveys

Data: Magnetic (M-Dz)