After a few days of eventful travel by way of Sturt's Duck Ponds, the Macquarie River was struck a few miles below Mount Harris, which had been an important landmark for explorers since the time of Oxley. The channel was dry, but the blacks reported a heavy flood as near at hand. Mitchell had often heard of sudden inundations appearing in an arid part of the country, and was anxious to witness so singular a visitation. Late in the still evening there fell upon his ear a dull murmur as of distant thunder, speedily followed by a cracking and crashing of trees, and in a few minutes more the river was overflowing its banks in a wide-spreading flood. The phenomenon is described as being grand in the extreme, and of so improbable a character as scarcely to be credited unless it had been witnessed. On the 27th the Castlereagh was reached, and the next day the party found themselves on the banks of the Darling. For many miles in both directions the river at this period was studded with pastoral settlements. Having crossed at Warley, near one of the stations, Mitchell now struck out for the Narran, the nearest point of which was reckoned to be about 35 miles distant. The intervening space was found to consist of choice pastoral country, covered with tall kangaroo grass. Commissioner Mitchell, son of the explorer, had previously traversed these parts, and this expedition soon "pulled up" his tracks. The line of the Narran River having thus been already explored, it was traversed as expeditiously as possible, and this part of the journey was over by the beginning of April, when the Balonne (pronounced Baloon) was sighted. Mitchell described it as the finest river he had seen in Australia, with the exception of the Murray. The current was very slight, but the water stretched out in long and beautiful reaches. The march was once more resumed, and the party moved along the line of this river till St. George's Bridge was reached, where the width expanded to 120 yards. At this point there is a chain of rocks stretching from bank to bank, which has always the appearance, and sometimes the convenience, of a natural bridge. It was this circumstance which led to its being called St. George's Bridge, a name which it still retains in common with the flourishing township that has sprung up in the vicinity.