For those of us with HAMS in their trucks, may I recommend the ECRA (East County Repeater Associations) 147.240 machine, PL 103.5 on Monument Peak for repeater comms in the desert.
Looks like Borrego Springs has a 440/70cm repeater, I have never tried it. 449.200, with a PL of 114.8
Simplex 146.535 works (cause its in memory on my radio
) but we can pick another if everyone agrees.