Calif OES has deployed 400 engines

https://twitter.com/Cal_OES/status/1430640779635040258

not sure on the actual numbers

the program works this way - OES gives a pumper to a local FD - the
local FD promises to staff the pumper with 4 firefighters and send
them anywhere in the state when requested by OES - otherwise the FD
can use the pumper as a reserve or secondary pumper for their local
needs - OES pays the salaries of the firefighters when they are on OES
duty

the large fires in California typically see responses from local
government engines plus CalFire engines + federal engines + OES
engines

OES has 2 statewide radio channels for OES engines - 154.22 R and 154.16 R