Dargan Shelter: Oldest human occupied Ice Age site found in the Blue Mountains

Archaeologists working with local First Nations groups have found the oldest human occupied Pleistocene site at high elevation (1073m) in the Blue Mountains, west of Sydney. The discovery indicates the cold climate at high elevation was not a barrier to human movement. These results align the Australian continent for the first time with global findings that cold climates did not prevent people from travelling and making shelters at these altitudes. Human artefacts, such as stone tools for cutting or scraping, and a sandstone grinding slab that may have been used for shaping wooden artefacts (needles, awls, or bone points for spears), were found in the ancient layers. The Blue Mountains, home to some of the oldest known rock shelters in Australia, have been inhabited for over thousands of years and this is the highest cave found with human activity, dating back to 20,000 years.

Dargan Shelter in the Upper Blue Mountains

The Dargan Shelter is a large rock shelter on Dharug Country in the upper Blue Mountains near Lithgow, NSW.

It is the highest elevation Pleistocene site identified in Australia. High elevation is defined as above 700 metres. It is believed to be the oldest human occupied site in Australia at high elevation (1073m), dating back to the Pleistocene when the Blue Mountains were frozen over.

It is below the modern subalpine zone in forest made up of tough-leaved eucalyptus trees, such as the blue gum, scribbly gum and mountain ash. Underneath the eucalyptus canopy, there is a variety of hardy shrubs, including banksias, wattles (acacias), and grevilleas.

Dr Way said it is possible the Dargan Shelter was a meeting place or a ceremonial site for people crossing the mountains from east to west and vice versa or for people spending substantial time travelling along the mountain range during the slightly warmer months. “People may have used the site as a stopover point while travelling to undertake ceremony or to access resources not found at lower elevations,” Dr Way said.

“While there’s no certain way of identifying which groups accessed the mountains in the deep past, it is likely that multiple groups were connected to this country.”

The study

New research published in Nature has found evidence of human occupation in an ancient rock shelter during the last ice age. The rock shelter, named the Dargan Shelter, is a high altitude (1073m) cave in the upper Blue Mountains, near Lithgow, indicating human occupation first occurred there around 20,000 years ago during the last ice age. It is the highest elevation Pleistocene site identified in Australia. Dr Amy Mosig Way led a team working closely with Dharug community members, and First Nations custodian Wayne Brennan, who is a rock art specialist and PhD candidate in archaeology at University of Sydney. The team discovered 693 stone artefacts, a small amount of faded rock art, including a child-sized hand stencil and two forearm stencils.

The Blue Mountains

People have lived in the Blue Mountains for more than 30,000 years adapting to multiple episodes of extreme climate change, including the last ice age. The mountains are home to some of the oldest known rock shelters in Australia.

However, the nature and extent of occupation in this region remains poorly understood in contrast to the better-known coastal areas.

In the ice age there were no trees, it was ~8 degrees cooler than today and water sources were frozen solid over winter. In the warmer months, there may have been a cold grassland tundra supporting mammals and birds.

Aboriginal Peoples today in the Blue Mountains

Today, Wiradjuri, Gomeroi, Darkinjung, Dharawal, Wonnarua, Gundungara and other groups hold traditional connections to this region. First Nations custodian, Wayne Brennan, said the Dargan Shelter is considered by local custodians to represent a family space of high cultural significance.

“The Blue Mountains are very important because what we have here is cultural heritage, through deep time, still intact in its natural environment,” Brennan said.

Stone artefacts found

A total of 693 stone artefacts were excavated across the three visits from April 2022 to March 2023. Many were stone tools possibly used for cutting or scraping. Most of the claystone tools were made locally but one came from the Jenolan caves area and another from the Hunter Valley region, indicating people were travelling from the north and south.

A notable late Pleistocene artefact was a sandstone grinding slab which dated to 13,000 years ago. It had two linear grooves characterised by distinctive abrasive wear consistent with shaping by abrasion of bone or wooden artefacts such as needles, awls, bone points and nose points.

A notable early Holocene find (post ice age) was a basalt anvil. It consisted of a split river pebble with distinctive sub-circular patch and impact marks consistent with cracking hard woody nut and seed shells.

Cold climate

High-altitude mountains pose many challenges for people to move around in. “Globally, new deep-time studies are changing how we think about these areas,” said Dr Way. “But in Australia, we still don’t know when people first lived in the cold, icy parts of the mountains. Research in Tasmania and the Australian Alps has only found evidence of people living at altitudes above the periglacial limit in the Holocene period. During the earlier Pleistocene period, researchers believed people only lived at lower, less icy elevations.”

During the ice age, periglacial conditions extended to the upper reaches of the Blue Mountains above 600 metres and temperatures would have been at least 8.2 degrees cooler than today with vegetation sparse. Pollen analyses, although with low counts, indicate no tree pollen at the site and regional pollen records indicate the tree line was 400 metres below the site. Little firewood would have been available locally and water sources would have been frozen through winter.

Despite these challenges, there is now a growing body of evidence for high-altitude Pleistocene human occupation in the Blue Mountains.

The Dargan Shelter findings from archaeologists at the Australian Museum and the University of Sydney, provide the oldest evidence of occupation above 700 metres in Australia, and the first site with definitive evidence for repeated occupation well above the tree line during the last ice age.

Dr Amy Mosig Way, Scientific Officer Archaeology, Geosciences and Archaeology, Australian Museum Research Institute.

This research is funded by the Australian Museum Foundation.