These are 3 Grumman S-2T air tankers owned by the State of California and operated by contract. Two of these are departing with full loads of retardant and one (in the middle) is available for dispatch. The S-2s were first introduced in 1952 and were used for anti-submarine warfare until 1976. These are converted military veterans.
This is a Lockheed P-
I was told that #10 was in the process of having one of its radial piston engines replaced (no, they weren't using a hangar to do this).