Walshs Pyramid, Wooroonooran National Park Tropical North Queensland

Nature, culture and history

    View from the summit of Walshs Pyramid, Wooroonooran National Park. Photo: Tamara Vallance.

    View from the summit of Walshs Pyramid, Wooroonooran National Park. Photo: Tamara Vallance.

    Natural environment

    Wooroonooran National Park is within the Wet Tropics World Heritage Area (WTWHA). Proclaimed in 1988, the WTWHA extends for about 450 km between Cooktown and Townsville. Consisting of nearly 900,000 ha, vegetation is primarily tropical rainforest, but also includes open eucalypt forest, wetlands and mangrove forests. The WTWHA meets all four natural criteria for World Heritage listing. These criteria recognise the area’s exceptional natural beauty and the importance of its biological diversity and evolutionary history, including habitats for numerous threatened species. The WTWHA also has cultural significance for a number of Aboriginal people who have traditional links with the area and its surrounds.

    For more information visit the Wet Tropics Management Authority’s website.

    The formation of the pyramid

    The rock forming this mountain is not particularly unusual. It is part of a granite intrusion that underlies the Bellenden Ker Range, the backbone of Wooroonooran National Park.

    The oldest rocks in the range formed about 360 million years ago as compacted sediments on the sea floor were caught in a squeeze between opposing forces to the east and west. These enormous forces pushed the sediments up to form huge mountains, transforming sediments into tough metamorphic rocks. Limestone sediments created the rocks of the Chillagoe region while sand, mud and gravel created the metamorphic rocks found commonly throughout the WTWHA.

    It is difficult to imagine rocks acting like liquids, but from time-to-time large pools of molten rock (magma) pushed up into the earth’s solid crust. Less dense, and therefore more buoyant than the rocks above, this magma squeezed through the older metamorphic rocks. In many places the magma did not make it to the surface, but slowly cooled and solidified to form bodies of granite deep underground. All this happened between 310 and 260 million years ago.

    Granite is particularly hard, so when the upper layers of metamorphic rocks were worn away by running water the granitic intrusions were left standing. This process formed Queensland’s highest peaks, Bartle Frere and Bellenden Ker, as well as Walshs Pyramid.

    Vegetation

    The first section of the walking track follows a steep, narrow spur through open woodland. White mahogany Eucalyptus portuensis and pink bloodwood Corymbia intermedia are common. At about the halfway point the vegetation becomes sparser, dominated by casuarinas, acacias and numerous grasstrees Xanthorrhoea sp.

    As the soil becomes shallower towards the summit, trees are more stunted and shrubs dominate, along with grasses and rock ferns. An interesting plant known as the porcupine bush Borya septentrionalis grows here (and on other steep, rock outcrops in the WTWHA). With a spiky appearance rather like spinifex, this plant spreads over rock surfaces where there is a good water supply, creating dense tufts and mats as plants grow together. It produces a rounded flower head with clusters of small white flowers in spring and summer. During the dry season, as this habitat becomes less moist, the plants turn a brilliant orange but when rain falls they become green again. For this reason, the plant has another popular common name—the resurrection plant.

    Culture and history

    In the 1870s, the mountain was named after the Queensland Government Minister of Works, the Honourable William Henry Walsh.

    Every year in August, this mountain is the focus of the Great Pyramid Race. This race involves runners completing a 12 km course from the middle of nearby Gordonvale to the summit of Walshs Pyramid and back. Some complete the course in less than 1.5 hr, while the average person takes 5-6 hr for just the steep 6 km return walk from the base to the summit and back.