King's Australia volume 1 page 291.) ...
It appears therefore that this main range contains within it the sources of Roe's River, Prince Regent's and Glenelg Rivers, most probably the Fitzroy, and those that run into Cambridge Gulf and perhaps others that have their embouchures between this last and Admiralty Gulf.
From an accident having occurred to the only barometer we could carry with us I am unable to state the elevation of the highest land we reached above the level of the sea; but the appearance of the country on the coast does not give the impression of any very elevated ground existing near it.

This however is owing to the great height of the shore cliffs and the gradual rise of the land towards the interior.

The following observations, made with the barometer before it was broken, will show however that the altitude of the country at no great distance from the coast is considerable.
MACDONALD'S RANGE.
Our first encampment was on the banks of a small river at a spot 2,640 feet from the sea.

This river ran through a deep and narrow valley, descending with a nearly regular slope from a tableland of sandstone, in which it took its rise about seven miles inland.

At this encampment the height of the bed of the river above the level of the sea was 188.76 feet, as found by the mean of several very accordant observations, which, at the same average slope, gives an elevation of about 377 feet for the height of a spot on its banks distant only one mile from the sea; and if we conceive the average increase of elevation to the sandstone tableland to be only 200 feet in every mile (and I believe it to have been more) we shall have 1400 feet for the elevation of the tableland which formed one of the highest parts of Macdonald's Range.
ELEVATION OF HILLS.
After passing across this range we again descended rapidly into the low country, the face of which is much broken by conical hills composed of basalt.