Nomenclature
It is not known where the name "gammon" comes from. Warren Bonython has a number of suggestions: it might be "gammon" the verb meaning "hoax" in reference to the thick scrub on the ranges (he notes an area near Adelaide called 'Humbug Scrub' as precedent). He settles for the meaning of gammon as a piece of bacon, saying that Gammon Hill does, under "certain conditions", look like a piece of bacon. Hearsay claims the Blue Range is named for the fact that, its immediate surrounds being so rugged, it's usually seen as a blue haze in the distance!
The Aboriginal name for the area is Arkaroo, the name of a legendary great snake. Arkaroo is reputed to have drank up all the water in Lake Frome, but, upset by its saltiness, he wriggled into the depths of the ranges, where his upset stomach continues to rumble to this day. The booming noises which are heard in the ranges today are thought to either be wind whistling through the narrow gorges or (more probably) large rockfalls. Arkaroo is the origin of the placename Arkaroola, used in several contexts in the area (also as the name of a station south of Wilpena).
Read more about this topic: Vulkathunha-Gammon Ranges National Park