A Santa Fe photo showing a pair of GP-30's hauling a unit train of potash in 1963, location not specified.
The GP-30 was a Bo-Bo type of which 948 were built between July 1961 and November 1963. Of these 85 (road numbers 1200-1984) went to Santa Fe. They were fitted with a turbocharged EMD 56703 prime mover with a 2250 hp (1680 kW) output. An interesting modeler's page is here