Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KB4MRU callsign genealogy
Currently held by BAY AREA MOUNTAIN RESCUE UNIT
The FCC publishes a previous_call_sign on
every amateur license — a self-link to the licensee's prior callsign.
Following those links produces the chain below.
Previous callsigns
Older callsigns held by KB4MRU's current licensee, walking backwards.
- KO6LPUcancelledBAY AREA MOUNTAIN RESCUE UNITCAgranted 2025-12-12cancelled 2026-01-03
Successor callsigns
Callsigns held now by people who previously held KB4MRU.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KB4MRU, oldest first.
- DEEM, DONALD A GA1994-11-21 → cancelled 2006-11-22
- Bay Area Mountain Rescue Unit CA2013-03-05 → cancelled 2025-03-06
- BAY AREA MOUNTAIN RESCUE UNIT CA2026-01-03 active