See area 12 on Aerial Photo Map.
The Picnic Ground is the area north of the creek. The original "Conservation Area" along the creek was fenced off to exclude livestock in 1978. This is the fence you come to when you cross the footbridge in the picnic area and walk south. In the 1980s another fence was added further south - the area between the two fences is the "conservation zone". On the aerial photo the fence closest to the creek is hard to distinguish from the maze of tracks, so I have not tried to show it on the map. In fact area 12 on the map corresponds roughly to the area mapped by Robertson as having a high diversity understory of native Wallaby Grasses and Spear Grasses (with some areas of Kangaroo Grass), apart from the eastern end which had lower diversity.