A B S T R A C TThe imperiled Clark's crayfish, Euastacus clarkae Morgan (1997), was described from a handful of juvenile specimens collected from one location in 1981. The Australian Crayfish Project recently completed an intensive field survey project to better define its distribution, habitat, biology and conservation status. Euastacus clarkae is restricted to headwater reaches of highland streams feeding the Hastings and Forbes rivers, at elevations ranging from 670-1150 m. The entire Hastings River catchment (3846 km 2 ) was surveyed and established the Extent of Occurrence for E. clarkae at 200 km 2 . The distribution was almost entirely located within Werrikimbe National Park where the species was locally abundant. We recommended conservation down listing from Critically Endangered to Endangered and present information to support future conservation efforts and allow specific management plans to be drafted for this rare, highland species. To assist with identification we provide a key to this and other Euastacus found in the Hastings and adjoining drainages.