Aborigines were first living in the ACT around 21,000 years ago. Their presence was confirmed with the excavation of the Birrigai rock shelter, an ancient camping place that was in use until the middle of the 19th century. The shelter can be accessed via the 3km Birrigai Time Trail, marked on the left before the reserve visitor centre.
Screenmakers has been involved in creating signage at Birrigai and Tidbinbilla for many years, including information signs for the Rock Cycle Pathway, which details the timeline of rocks in the area, directional signs for Birrigai Outdoor School and track-marking signs. The signage design for both sites was prepared by Kim Tatnell from Big Island Graphics for PCL / TNR.
Along the Birrigai Time Trail at Tidbinbilla Nature Reserve, traces of the previous inhabitants can be seen in boulder shelters, camps and tool-making sites.