The range through which the Isaacs passes is composed of sandstone, and strikes from north-west to south-east.

In its rocky caves, wallabies, with long smooth tails, had been seen by Brown; they were quite new to him, and, as he expressed himself, "looked more like monkeys than like wallabies." Mr.Gilbert and Charley came on two flocks of emus, and killed two young ones; and Charley and John Murphy hunted down another; Charley fell, however, with his horse, and broke a double-barrelled gun, which was a very serious loss to us, and the more so, as he had had the misfortune to break a single-barrelled one before this.
The weather continued showery; loose scud passed over from the east and south-east, with occasional breaks of hot sunshine.

The Corypha palm is frequent under the range; the Ebenaceous tree, with compound pinnate leaves and unequilateral leaflets, is of a middle size, about thirty feet high, with a shady and rather spreading crown.
We have travelled about seventy miles along the Isaacs.

If we consider the extent of its Bastard-box and narrow-leaved Ironbark flats, and the silver-leaved Ironbark ridges on its left bank, and the fine open country between the two ranges through which it breaks, we shall not probably find a country better adapted for pastoral pursuits.

There was a great want of surface water at the season we passed through it; and which we afterwards found was a remarkably dry one all over the colony: the wells of the natives, however, and the luxuriant growth of reeds in many parts of the river, showed that even shallow wells would give a large supply to the squatter in cases of necessity; and those chains of large water-holes which we frequently met along and within the scrubs, when once filled, will retain their water for a long time.