Here's the Wikipedia thumb-nail history. Looks like SDIY was operator and SDIY power was used on this excursion.
In March 1984, the Metropolitan Transit Development Board signed an agreement with the shortline holding company Railtex to resume freight service on the SD&AE line from San Diego; Kyle Railways discontinued freight operations in 1983. The new railroad, the San Diego and Imperial Valley Railroad (SDIY), which commenced operations on October 15, 1984, did not want to invest the $5.5 million necessary to repair the collapsed tunnels and bridges in the Carrizo Gorge. CZRY Shareholders Gary Sweetwood and Benny L. Wright of local construction company, East County Dirt Works, however, believed that the investment would be worthwhile and negotiated trackage rights on the line. The agreement required a fee of 6.9% imposed by SDIY, for the gross revenues from any freight on the SD&AE's Desert Line and a fee of 2% by the SD&AE Railway Company.