Contrary to previous literature, P. xanthopus had not been recorded in western New South Wales before its existence was reported by Fox (1966). There is only one geographically isolated population of less than 250 animals in two separate colonies in the Gap and Coturaundee Ranges, where they are confined to two cliff systems and two outcrops. Their distribution is therefore more limited than first reported by Wilson et al. (1976). They were more widespread in the past, being found also in the Barrier and Bynguano Ranges. These conclusions have been reached from data collected from: (I) a large-scale low-level aerial survey and subsequent ground inspections to record this species' presence in specific locations in north-western New South Wales; (2) a systematic detailed survey of the Gap and Coturaundee Ranges to establish its pattern of habitat use from the accumulated density of faecal pellets; (3) lowlevel aerial surveys over these and other areas, by helicopter, to confirm the results of earlier surveys and check on reported sightings. The results of this study are being used for the management of this rare rock-wallaby in New South Wales. It is recommend that this species be re-established in the Bynguano Range. Fig. 2. Locations of zones surveyed for P. xanthopus: zone 1, southern Grey Range; zone 2, Bulloo Overflow Catchment; zone 3, Barrier Ranges; zone 4, Eastern Hills Complex. Zone 2The following 1 : 250000 topographical maps were used for the ground survey: Milparinka, SH 54-7; Urisino, SH 54-8; Cobham Lake, SH 54-11; White Cliffs, SH 54-12; Broken Hill, SH 54-15; Wilcannia, SH 54-16.The habitat factors recorded at each site were: rock type and texture, boulder size, and the presence of water within 2 km of the nearest rockpile.The survey was conducted in four conveniently divided zones (see Fig. 2), as follows.