In the early part of the 19th century, the region was populated by Scots-Irish immigrants, and the owner of the farm was one of them. In the Gaelic language, "banshee" is a female spirit and "reeks" refers to hills and dales.
The nature preserve's website explains the origins of the strange name.
"According to the story, one night the farmer went into the town of Leesburg to attend to personal business and also paid a visit to the local saloon. While traveling back to the farm, the wind howled and the animals of the night made much noise. Upon arriving home, the farmer was in such a state of mind that he claimed that he heard a banshee on the reeks. The phrase was altered over the years and the area became known as "Banshee Reeks".
I stole the story and used it as the legend behind my little town. I had to change the name, though. "Reek" may be a hill in Gaelic, but in modern day English it means "stink." That's not the kind of thing you want associated with you idillic (albeit slightly haunted) small town. A small rivulet called "Goose Creek" crosses the preserve and that gave me the idea for a name. That's how "Banshee Reeks" became "Banshee Creek."
In my mind, the town looks a lot like Middleburg, VA (except it's not as wealthy, it has a lot more Victorian architecture, and it has a lot more ghosts). You can see some inspiration pictures in Pinterest. You can also visit Banshee Reeks and even camp out for the night. Who knows? You might find a Banshee in the "reeks."