Here's what I could put together from what's still available online (some of it shouldn't be!), but bear in mind the HF frequencies can change from month to month to deal with propagation changes:
USAF MARS Regions:
Region 1: PE NY NJ DE RI MA NJ NH ME
Region 2: MD VA WV KY TN NC SC AT AL FL
Region 3: ND SD NE KA MI IO MO WI IL MN IN OH AK
Region 4: TX OK AR LA AR MS
Region 5: WA OR ID MT WY UT CO
Region 6: CA NV AZ NM
Region 8: HI
Region 1 ECOM Nets:
ROMEO CHARLIE
ROMEO BRAVO
Region 2 ECOM Nets:
ROMEO FOXTROT
Region 3 ECOM Nets:
ROMEO GOLF (RG) 3308.0 KHZ (USB) (Primary Local Nights)
ROMEO HOTEL (RH) 4517.0 KHZ (USB) (Primary Local Nights)
ROMEO INDIA ( RI ) 7305.0 KHZ (USB) (Primary Region-Wide Days)
Region 4 ECOM Nets:
ROMEO JULIET (RJ) 3370.6 KHZ (USB) (Alternate Local and Nights)
ROMEO KILO (RK) 4464.6 KHZ (USB) (Primary Local and Regionwide Nights)
ROMEO LIMA (RL) 7302.1 KHZ (USB) (Primary Regionwide Days)
Region 5 ECOM Nets:
ROMEO NOVEMBER
ROMEO OSCAR
ROMEO MIKE
Region 6 ECOM Nets:
ROMEO PAPA (RP) 3296.0 KHz (USB) (Primary Local & Nights)
ROMEO QUEBEC (RQ) 4575.0 KHz (USB)
ROMEO ROMEO (RR) 7457.0 KHz (USB) (Primary Region-Wide Days)
WHISKEY SIERRA SIERRA NOVEMBER ONE (WSSN1) 6996.0 KHz (USB)
HF/SSB Voice Liaison to SHARES as directed. Frequencies are normally
published in SHARES Readiness Notice
(One set of SHARES frequencies from diagram

5336.0 Khz (USB)
14396.5 Khz (USB)
HF/SSB Voice Liaison to FEMA as directed. Frequencies are as follows:
5211.0 KHz (USB) (FEMA’s Primary Callsign is WGY 912)
10493.0 KHz (USB) (FEMA’s Primary Callsign is WGY 912)
13956.0 KHz (USB or LSB) Often used for exercise checkins
ESSENTIAL ELEMENTS of INFORMATION (EEI) Event Identifiers
AIR CRASH --------------------------------------- FALLEN STAR
AIRBORNE POISONED GAS --------------------------- POISONED AIR
BIOLOGICAL EVENT -------------------------------- BAD BUG
BOMBING INCIDENT -------------------------------- LOUD BANG
BRIDGE DAMAGE/LOSS (MAJOR) ---------------------- LOST SUPPORT
CHEMICAL SPILL ---------------------------------- POISONED GROUND
CIVIL UNREST/RIOT ------------------------------- BAD MAGIC
DAMAGING HAIL ----------------------------------- FALLING ICE
EARTHQUAKE -------------------------------------- ROLLING THUNDER
FLOOD ------------------------------------------- TALL WATER
FOREST/GROUND FIRE ------------------------------ SCORCHED EARTH
GAS LEAK/EXPLOSION (MAJOR) ---------------------- HOT AIR
HEAVY WIND (Other than hurricane, or tornado) --- MIGHTY WINDS
HURRICANE --------------------------------------- HOWLING WIND
ICY ROADS --------------------------------------- BLACK ICE
INTERSTATE, BLOCKED/DAMAGED (MAJOR) ------------- BLOCKED LANE
MAJOR COMMUNICATIONS LINK DOWN ------------------ LOST COMM
NUCLEAR ----------------------------------------- NUCLEAR GRAYSTONE
OIL SPILL (WATER) ------------------------------- DARK WATER
POWER OUTAGE (MAJOR) ---------------------------- DARK DAY
SEARCH/RESCUE ----------------------------------- SECURE HAVEN
SEISMIC SEA WAVE -------------------------------- TSUNAMI
SHIP WRECK/INCIDENT ----------------------------- DEEP SEA
TERRORIST INCIDENT ------------------------------ HIDDEN SHADOW
TORNADO ----------------------------------------- VIOLENT TWISTER
TRAIN WRECK/DERAILMENT -------------------------- BROKEN TRACKS
VOLCANO ----------------------------------------- BRAZEN BRIMSTONE
WATER DAM BROKE/DAMAGED (MAJOR) ----------------- FAST WATER
WINTER SNOW STORMS ------------------------------ WHITE BLANKET
------------- Communications Support Identifiers -----------------
FEMA SUPPORT ------------------------------------ FEDERAL RESPONSE
JCS REPORT -------------------------------------- JOINT LIONS
NATIONAL GUARD & RESERVE SUPPORT ---------------- CIVIL COVER
NCS REPORT -------------------------------------- TOP COVER
NDMS SUPPORT ------------------------------------ MEDICAL LINK
SHARES SUPPORT ---------------------------------- COMMON FORTUNE