Take everything with a small grain of salt, I was scribbling and driving

Frequencies
863.2500 - control channel (full strength coverage from Ocotillo Wells on back to I-8 and the San Diego County line)
862.2500 - voice
856.4250 - voice
859.0000 - voice
Talk Groups
10992 - ALS -> Hospital (Pioneer Memorial?)
25424 - Ambulance service (Gold Cross?)
39312 - Law enforcement ("Station 9")
39408 - Law enforcement
39472 - Imperial County SO
41104 - "Contact PD before entering the scene"
41120
41344
41392 - Base ID'd as "El Centro"
41408
41424
42080
42544
The following San Diego talk groups were also active on this system
6896 - LE East Tac 1
6960 - LE East Tac 3 (Ongoing ops in desert campsites with SO, Parks, and RACES?)
10384 - CDF Dispatch
21296 - Inland Fire Admin
34560 - SO Rural Dispatch
34976 - SO Rural Tac 80
38656 - CHP Resident Tac 1
38880 - CHP El Cajon Dispatch
- Mike