Don - How are you defining a "true logging railroad"? If it's a railroad used directly in the logging then you would be correct and this is a major oversight. "Directly" meaning the track is laid pretty much temporarily in a section of land to be logged and the trees are felled in the immediate vicinity and loaded directly onto the rail cars. When the area is logged out, the track is usually pulled up and relaid to the next section.
What was happening largely from after WWII-on was that a "permanent" branch line track would be laid (or already there) to a re-load and trucks would go out to actualy falling sites and bring the loads to the re-load.
Now it's certainly true that here have been some minor attempts that could fall within the definition of "logging railroad". Examples would be Port of Tillamook Bay RWY's right of way logging back in the late 90's and (One version of) the Tacoma Eastern's doing pretty much the same thing in the mid-90's. Of course these examples only pass some of the "tests".
But what we are talking about are true logging operations that had existed for some time (i.e. -more than a few months) and had always been railroad logging. Incidentally, to my knowledge there was not any signifigant railroad logging done with diesels - if at all.
Let me poorly quote John Labbe "The rails went right up to the spar tree and the logs came in on the highline and were loaded directly onto the cars".
If your Verginny examples can past these tests then this Pacific Northwest-centric logging historian will admit I'm ignorant!
Regards, Lon