Tanker 96, Grumman TS-2A BuNo 136704, registered N416DF. The government-owned aircraft was operated by San Joaquin Helicopters for CDF (now CalFire).
N416DF was destroyed in an accident on October 5, 1998, and the one pilot aboard, Gary Nagel, was killed. The NTSB accident summary is here:
www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001211X11282
Additional information about the accident and the pilot can be found here:
www.wlfalwaysremember.org/incident-lists/261-gary-nagel.html
Both the tanker number (96) and the registration (N416DF) have been re-used for later aircraft.
Photographed at the CDF Paso Robles Air Attack Base
Paso Robles Municipal Airport (PRB / KPRB)
October 1996
US-2B 136704 at NAS Lemoore, June 1981:
flic.kr/p/kieZP2
Tanker 96 at Mather Airport, Sacramento, April 1997:
flic.kr/p/G4Mtv3
NOTE:
CDF = California Department of Forestry and Fire Protection
In 2007, CDF began to be known as "CAL FIRE."