East-central Iowa (IA)

Survey type M-A (magnetic; derived from analog data)
Flown by Aero Service Corporation
Date flown ?/68
Line spacing 1.6 (km)
Altitude 304.8 (m) above ground
Total distance 12,070 (km)
References
Counties Carroll - Jo Daviess - Rock Island - Whiteside - Benton - Black Hawk - Buchanan - Cedar - Clinton - Dallas - Delaware - Dubuque - Grundy - Hardin - Iowa - Jackson - Jasper - Johnson - Jones - Linn - Marshall - Muscatine - Polk - Poweshiek - Scott - Story - Tama
Overlapping surveys

Data: Magnetic (M-A)