Is there a legend to the city/area abbreviations?

Yes. Cities and other response areas are represented by the abbreviations shown below.

San Mateo County
ATNAtherton
BLMBelmont
BRDBroadmoor
BRHBurlingame Hills
BRMBurlingame
BRSBrisbane
BUTButano Canyon
CLMColma
DCYDaly City
DVNDevonshire Canyon
EICEichler Highlands
ELGEl Granada
EMLEmerald Hills
EPAEast Palo Alto
FCYFoster City
HILHillsborough
HMBHalf Moon Bay
KMTKings Mountain
LADLadera
LAHLa Honda
LTWLas Trancos Woods
MBHMoss Beach
MIRMiramar
MLBMillbrae
MNPMenlo Park
MOKMenlo Oaks
MONMontara
NFONorth Fair Oaks
PAPalo Alto
PALPalomar Park
PAPPalo Alto
PCFPacifica
PESPescadero
PRNPrinceton
PVYPortola Valley
RCYRedwood City
RWSRedwood Shores
SFSan Francisco
SFOSan Francisco International Airport
SKYSkylonda
SMOSan Mateo
SNBSan Bruno
SNCSan Carlos
SNGSan Gregorio
SOSSan Mateo County
SSFSouth San Francisco
WDSWoodside
WMPWest Menlo Park
WSBWest Selby

San Ramon Valley
ALAMAlamo
ALCOAlameda County
BLKHBlackhawk
CTYContra Costa County
DANDanville
DIABDiablo
SRSan Ramon
WCWalnut Creek

Yolo Emergency Communications Agency
ABArbuckle
CBClarksburg
CCCollege City
CLColusa County
CPCapay
DavisDavis
DNDunnigan
DVDavis
ELEl Macero
ESEsparto
KNKnights Landing
MDMadison
RBRobbins
SLSolano County
UCDUC Davis/TD>
WDWoodland
WNWinters
WSWest Sacramento
YCYolo County
YOYolo
ZAZamora

Chino Valley Fire
CHHCity of CHino Hills
CHOCity of CHino