03/31/2011. Remarks by Doug Duncan: "For service in Alaska and Greenland, in support of the construction and operations of the stations in the DEW (Distant Early Warning) line the USAF needed a large ski-equipped transport, and the C-130 was evaluated. The ski-equipped prototype was modified from a C-130A, s/n 55-021 c/n 182-3048, it first flew in January 1957 and was extensively tested by a joint USAF-Lockheed team at Bemidji, Minnesota, during Project Slide.
Following the successful conclusion of the test, the USAF requested Lockheed to modify twelve of its 45 C-130A-45-LMs (c/n 182-3160 to 182-3204), which it had ordered under the s/n 57-453 to 57-497 in the FY 1957. These twelve, s/n 57-484 to 57-495, were finished as C-130D-LMs. Six were later converted to C-130D-6 standard by removal of their skis. Furthermore, two C-130As (57-473 and 57-474) were modified as C-130Ds but later were returned to their original configuration. The pictured aircraft was stored at the MASDC at Davis-Monthan AFB, Tucson, Arizona on June 2, 1976, where it still is as of this day.
As for the apparent discrepancy in the serial number, seen as O-70488, the USAF introduced an O-prefix (O for Obsolete; not a zero) beginning in 1955 to the serial numbers for aircraft as they became ten years old. This means that this particular aircraft carried 70488 on its tail up until 1967, at which time the O-prefix was added. This system itself became obsolete in 1972, and it was some years before all of the already applied O-prefixes had disappeared.
I'm afraid this shot's a little soft due to a combination of long lens and slow shutter speed thanks to the cloud cover, but this was the only chance I got to capture the prop tip contrails."