The Mil VHF Hi band continues to slowly evolve into a whole new bandplan. See our Milcom column in the August 2006 issue of Monitoring Times for complete details and additional frequencies.
Via a public domain source: Navy-Marine Corps MARS packet operations in the Northeast US has moved from 142.700 to 140.625 MHz. This is the second ref we have seen to 140.625 MHz being used by MARS. Looks like MARS now has a new nationwide VHF frequency of 140.625 MHz.
A new MARS repeater pair has been also announced in the public domain.
148.950/148.350 MHz is being used at NAS Willow Grove with a 77 Hz PL tone. If your local area MARS repeater disappears, check either of the two freqs above for possible new activity.