Black Hills (SD)

Survey type M-A (magnetic; derived from analog data)
Flown by U.S. Geological Survey
Date flown 08/67
Line spacing 1.6 (km)
Altitude 2286 (m) by barometer measurement
Total distance 1,971 (km)
References
Counties Custer - Pennington
Overlapping surveys

Data: Magnetic (M-A)