The Cooks River/Castlereagh Ironbark Forest (CRCIF) is a scattered, dry sclerophyll, open-forest to low woodland and scrubland which occurs predominantly in the Cumberland subregion of the Sydney basin bioregion, between Castlereagh and Holsworthy, as well as around the headwaters of the Cooks River. The Cooks River Clay Plain Scrub Forest is a component of this ecological community, though both belong to a larger occurring community called the Temperate Eucalyptus fibrosa/Melaleuca decora woodland.