Castlereagh River
The Castlereagh rises 20 km west of Coonabarabran in the heart of the Warrumbungle mountains at an elevation of about 850 metres. From its commencement upstream in the mountains the river initially flows east through the town of Coonabarabran. It then arcs round south and southwesterly to the village of Ulamambri, then south to Binnaway, and SSW to the small town of Mendooran which lies at the eastern side of the river's hook-shape. From here the Castlereagh flows in a westerly direction at the flattened bottom of the hook and then turns north-westerly towards the town of Gilgandra. From Gilgandra it continues to run northwesterly across the plains through Gulargambone and Coonamble, then continuing across expansive plains, with no urban centres, where elevations are less than 200m, until it joins the Macquarie River at its uppermost reaches beyond the Macquarie Marshes. Its confluence with the Macquarie is about 65 km SW of Walgett. Not far from the Castlereagh/Macquarie confluence the Macquarie itself joins the Barwon River at a place about halfway between Walgett and Brewarrina.
River Roach
From Stambridge Mills eastwards, the River Roach is tidal and becomes a wide river. It passes Great Stambridge Hall, Mucking Hall, Barton Hall and Roper's Farm. Barlinghall Creek joins Potton Creek and is called "The Violet" before it joins the Roach on the right bank. From here the Roach is about wide. It passes Paglesham, significant for its native oysters and the location of Charles Darwin's HMS "Beagle" which lies under the mud west of Paglesham's boatyard and slipway. After being retired from the Royal Navy in 1845, the vessel was used by the Coast Guard as a watch ship. It was moved to the centre of the river near Paglesham in 1850, eventually becoming "Watch Ship No. 7". Its condition deteriorated, and it was moved to the shore in 1863, to be sold for breaking up in 1870. A six-year archaeological investigation ending in 2008 concluded that much of the vessel still lies beneath of mud near to the Paglesham hard.