Survey number: 173 & 193 (Pat Hill numbers)
Name: Copper River '54 and Copper River '55
Date flown: 1954 and 1955
Company: USGS
Flight specs: 2 mile spacing, north-south, 4000 ft barometric.
Instrument: 

Digitized by: Esther Castellanos, August 1993 

Map scale: 1:125,000 

Datum: arbitrary datum

Publication: USGS Map GP-156

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)

Background: These data digitized under supervision of Rick Saltus, USGS,
            for inclusion in grid compilation for Interior Alaska
            (for published USGS Map GP-1014).  Work done in cooperation
            with John Meyer, State of Alaska, Division of Oil and Gas.