460.6375 - The frequency was originally licensed to the Highlands Police Dept as a low-power channel (2 watts).
In 2000, Mission-St Joe also licensed the frequency for base use in Asheville.
I cannot tell if the usage by Highlands and MSJ is related (landing zone setup / control at the hospital in Highland ?), or just coincidental.
460.5125 - Memorial Mission Hosp (Mission St Joe's former name) had a license for this frequency, under the callsign of WPDH865, until 1999. Information on this license, and most licenses before 2000, is not available on the FCC online database.
MMH licensed the frequency for medical use, which included a variety of purposes. Similar licenses, along with police and fire licenses, are all now a part of the PW class of license, but I could not find that MMH continued to license 460.5125 under a new or converted license.
Another frequency to monitor would be 123.050 MHz. This is a unicom aero channel, so you will hear other non-medical traffic on it. MSJ has a base station license on the channel, and can provide flightwatch for other med helos and aircraft passing through the Asheville area.
Jeff