The information on that site is extremely outdated. Desert Comm doesn't even exist anymore and fire has had some reorganization of its dispatch and response operations.
Very true. Can you put together an updated list and put it in the Wiki for SBCo?
Here's the general layout for towers (as I remember them). My first hand knowledge is 10 years old, but unless they have added new towers for dead spots, the basic information is still valid:
System 1 (1-Fire-? // 1-DC-??): Victor Valley area, from top of Cajon to about Wild Wash on I-15, out 247 towards Lucerne Valley until it fades, up 395 to the ridge just south of Kramer Junction. The system tower is on Quartzite Mountain just north of Victorville.
System 2: Barstow area from Wild Wash to Afton Canyon on 15, Kern Co (58) to about Kelbaker (40). 395 from s/o Kramer to s/o Red Mountain. Conventional 800 repeaters in Red Mountain, Trona, Baker, and Mountain Pass fill in the areas north of these locations where the trunked systems don't work. The system tower is on Flash II Peak just north of Barstow
System 3: Lucerne Valley basin, Fill-in between Barstow and the start of System 5 coverage west of Needles, Fill-in in portions of the Baker beat area that have line of sight to Rodman Mountain NE of Lucerne Valley. System 3 actually has (had) a large footprint in all directions as long as it wasn't shadowed by mountains, due to the height and location of Rodman.
System 4: Morongo Basin area, from top of Morongo Grade on 62 to about 177 east of 29 Palms, and out Amboy Rd to Sheephole Pass. Two main towers at Paxton (Yucca Vly) and Donnel Hill (29P).
System 5: Needles and Colorado River area. Main tower on Spirit Mtn in NV, with conventional 800 fill-in repeaters for Parker Dam and Havasu Landing resident posts.
My experience was with the Desert systems, so any information I have on Systems 6-10 is going to be very dated, and likely needs updating.
System 6/7: San Bernardino Valley area system, covers from Yucaipa to LA Co line. The systems actually use the same towers and frequencies, but are split to divide the call volume and to better manage the talkgroups.
System 8: Mountain areas (Big Bear/Lake Arrowhead)
System 9: Used to be West End Police Agencies
System 10: Didn't exist when I was there, but I think it is San Bernardino City's system.
I hope that helps. I'm sure some of that has changed, but (especially with the desert stuff) this should get you in the ball park.