The CERRA property is significant for its outstanding examples of the earth's biological and geological evolutionary history, for its representations of ongoing geological processes and biological evolution, and for its provision of habitat for threatened species of plant and animals.

CERRA is a serial property, encompassing approximately 50 reserves between Newcastle and Brisbane. These are linked by their shared importance in conserving this region's globally significant rainforest. Tooloom National Park is in the northern or border section of CERRA. In its vicinity, other CERRA reserves include (in NSW) Toonumbar National Park (part only), Captains Creek, Acacia Plateau, Wilsons Peak, Mount Clunie and Mount Nothofagus Flora Reserves, and (in Queensland) Mount Barney and Main Range National Parks and Killarney State Forest.

Park World Heritage values include:

• Large stands of hoop pine, an ancient primitive conifer representing the "Age of the Conifers" - the Jurassic Period;
• A concentration of primitive flowering plants originating in the Early Cretaceous which complements the centre of endemism in the Wet Tropics World Heritage property in north Queensland;
• As part of the CERRA property, the most diverse assemblage of relict angiosperm taxa representing the primary radiation of flowering plants in the mid-Late Cretaceous;
• Subtropical rainforest. Vegetation that was more widespread in the Late Cretaceous / Early Tertiary (the 'golden age' of flowering plants), and provides a unique record of evolution.
• A representation of aspects of the rise of modern dry-adapted floras;
• Outstanding examples of relict vertebrate and invertebrate fauna from ancient lineages linked to the break-up of Gondwana;
• Rainforest which provides an outstanding benchmark for the study of the ongoing evolution of plant and animal communities of Gondwana origin;
• The principal habitat for many species of plant and animals of outstanding universal significance; and
• Many threatened species considered potentially vulnerable to extinction.