This sub-region consists of the Murchison and Yalgoo IBRA bioregions.

The Yalgoo bioregion is characterised by sand and alluvial plains, low ranges and lakes. Mulga or bowgada shrublands dominate in the east, with sand plains, heathlands and some eucalypt shrublands in the western parts. Tenure is pastoral leasehold and sheep grazing is the main enterprise type. Mining is also important in the bioregion. Major population centres are Yalgoo and Paynes Find.

In the Murchison IBRA, vegetation is predominantly low mulga woodlands. The region is one of the main pastoral (sheep and cattle) areas in WA, although mining (gold, iron and nickel) is more important to the bioregion’s economy. Major population centres are Leinster, Leonora, Meekatharra, Mount Magnet, Laverton, Cue and Wiluna.

In recent years there has been a strong trend in enterprise type away from merino sheep to meat sheep and rangeland goats. This was due to low wool prices, high meat prices, difficulty in finding labour for wool enterprises and wild-dog predation on sheep. Infrastructure on many stations, especially fencing, is not being maintained. This is partly the result of the move away from merino sheep.

The Murchison bioregion has an arid climate with predominantly winter rainfall, and theYalgoo bioregion varies from semiarid to Mediterranean.