It encompasses a 130 km long coastline of spectacular limestone cliffs rising above vast untouched beaches, extensive woodlands, dramatic granite outcrops and a system of wetlands including the perched freshwater Lake Jasper. The Park harbours rare species of fauna and flora and provides habitat for quokkas and woylies. It is also the locale of an ancient cultural landscape, with Aboriginal quarries and chipping floor sites dating back 6000 years. Many of these are now submerged, indicating that Lake Jasper was once an inhabited woodland. The South West Coalition of Aboriginal Corporations and Custodians of Traditional Lands has lodged a native title claim over the area.
Lake Jasper is the largest freshwater lake in the south-west of Western Australia.
About 10 metres deep, Lake Jasper covers 440 hectares, and its associated swamps 80 hectares. The water is fresh and clear. It appears that most of the lake's water supply comes from groundwater. Among the 27 South Coast Wetlands, Lake Jasper was ranked third for the number of species recorded, the number of individuals recorded in the summer survey 1991-92. In overall importance it came second.