Survey number: 177 (Pat Hill number)
Name: Nushagak Basin
Date flown: 1954
Company: USGS
Flight specs: 2 mile spacing, east-west, 1300 to 1500 ft barometric.
Instrument: 

Digitized by: DIGIMAP (Esther Castellanos, January 1997)
Map scale: 1:125,000

Datum: arbitrary datum

Data format: Ascii format, XYZ records 
             Longitude (degrees), Latitude (degrees), Total Field (nT)
             written with FORTRAN format: (f10.5,x,f10.5,x,f8.1)

Reference: Henderson, John R., Vargo, Joseph L. and others, 1963, 
           Aeromagnetic Map of Part of the Dillingham Quadrangle, Alaska,
           USGS Geophysical Investigations, Map GP-352, 1 sheet, 
           1:125,000.