Copperhannia Nature Reserve is located on the edge of both the South Eastern Highlands and NSW South Western Slopes Bioregions and contains a reasonably large remnant of grassy and shrubby dry sclerophyll woodlands and forests on rolling to steep hills. The Creekside Apple Box Woodlands, Low Altitude Dry Woodlands and Granite (Gully) Woodlands found in the reserve are considered to be vulnerable and inadequately conserved.
The reserve is located in the Lachlan River Catchment. The majority of the creeks in the reserve flow west into the Abercrombie River and eventually join the backed up waters of Wyangala Dam before reaching the Lachlan River.
Five Aboriginal sites have been recorded within Copperhannia Nature Reserve, as well as an old gold mining shaft. There is anecdotal evidence that the reserve may have been used by bushrangers.
