The Murchison is a loosely defined area of Western Australia located within the interior of the Mid West region. It was the subject of a major gold rush in the 1890s and remains a significant mining district. The Murchison is also included as an interim Australian bioregion. The bioregion is loosely related to the catchment area of the Murchison River and has an area of 281205 km2.

Geography

The landscape is characterised by low hills and mesas, separated by colluvium flats and alluvial plains. The western portion of the bioregion is drained by the upper Murchison and Wooramel rivers, which drain westwards towards the coast. Together with Gascoyne bioregion, it constitutes the Western Australian mulga shrublands ecoregion. Population is scattered; the largest population centres are Meekatharra, Mount Magnet, and Leonora, with smaller mining and pastoral towns at Yalgoo, Sandstone, Cue, Wiluna, and Leinster.

Subregions

The Murchison bioregion has two subregions:

Political boundaries

Local government areas within the bioregion include the Shire of Yalgoo, the Shire of Mount Magnet, the Shire of Murchison, the Shire of Cue, the Shire of Sandstone, the Shire of Meekatharra, the Shire of Wiluna and the Shire of Leonora.

Climate

The climate is arid, with rainfall predominantly in the winter months.

Flora and fauna

The predominant plant community is low mulga woodlands and shrublands, characterized by mulga (Acacia aneura), with an understory of herbaceous ephemeral plants and bunchgrasses. Other plant communities include saltbush (Atriplex spp.) shrubland on calcareous soils, low samphire (Tecticornia spp.) shrubland on saline alluvium, and hummock grassland on red sandplains.

Land use

The Murchison is one of the main pastoral areas in Western Australia, dominated by large pastoral leases on Crown land operated as sheep and cattle stations. Mining (gold, iron and nickel) is the major contributor to the region's economy. There are extensive mining areas, with a large number of abandoned historical mining towns and settlements. The Australian Square Kilometre Array Pathfinder radio telescope is located nearby, and was officially opened in October 2012.

Protected areas

Purchase of pastoral leases by the Western Australian Government increased the area set aside for conservation purposes from about 0.5% of the bioregion in 1998 to 6.7% in 2004. Protected areas include: