The Murchison River is the second longest river in Western Australia. It flows for about from the southern edge of the Robinson Ranges to the Indian Ocean at Kalbarri. The Murchison-Yalgar-Hope river system is the longest river system in Western Australia. It has a mean annual flow of 208gigalitres, although in 2006, the peak year on record since 1967, flow was 1,806gigalitres. Basin The Murchison River basin covers an area of about in the Mid West region of Western Australia. It extends about inland from the Indian Ocean, onto the Yilgarn Craton east of Meekatharra and north of Sandstone. Rain generally falls in the upper basin during summer cyclones, so for much of the year the Murchison River does not flow, leaving a dry sandy river bed and intermittent permanent pools. The eastern reaches of the basin contain large chains of salt lakes, which flow only following rainfall. The drainage lines from these lakes merge to form the Murchison River about north-northeast of Meekatharra. From here the river flows west, then southwest, then west to the Indian Ocean. Within the basin are the towns of Kalbarri and Meekatharra; the hamlets of Ajana, Binnu, Barrel Well and Murchison; and the mining ghost towns of Galena, Geraldine, Abbotts, Chesterfield, Yaloginda, Reedy, Nannine, Quinns, Burnakura and Gabanintha. Course The Murchison River rises on the southern slopes of the Robinson Ranges, about north of Meekatharra in central Western Australia. From there it flows in a westerly direction for about to its junction with its largest tributary, the Yalgar River, then west for another before turning south-southwest for , at which point it is joined by the Roderick River, about east of Murchison Settlement. Another to the south-southwest it joins another important tributary, the Sanford River. Over the next it makes a number of sharp turns, taking it about to the west. It then flows to the southwest, flowing under the North West Coastal Highway at the Galena Bridge. Entering the Kalbarri National Park, it flows first to the northwest and then to the north, flowing through the Murchison Gorge, and passing through a number of tight bends known as the Z Bend and The Loop respectively. It eventually turns to the southwest, passing through one more dogleg before discharging into the Indian Ocean at Kalbarri, the only town on the river. Murchison Gorge Murchison Gorge is a deep gorge in near pristine condition. It