Just for the heck of it, I tried using ARC 536 Internet download feature to find this. I too was unable to do so, trying numerous counties and statewide.
They can be located in Sentinel, however. I suppose you could create a FL via Sentinel, program it into your scanner, then read it from your scanner using ARC. But I agree, this should be something you can do in ARC directly. So Gommert might need to check on this.
I did the ARC Frequency search and was able to find the 155.235 frequency that way, so ARC does have the ability to find it in the database, but they can't be found in the desired way.
There wasn't a county associated with the frequency, so that might be a possible reason.
Another reason is because they are not associated with an "agency" and ARC is having a problem finding them. I looked for Kentucky's and found them listed as "KY Air Evac Helicopters" for agency.
Something is definitely amiss. So the question is this an ARC issue or RR database issue, or both?