From the excerpt of Ensign Robert Dale’s August 1830 report (Exploration Number 1830/212 – see below) it can be seen that he made an exploration with Captain F.C. Irwin in April 1830, Exploration Number 1830/97 Ensign Robert Dale’s expedition to trace the Swan River, 7-22 April 1830.
In his report of his January 1834 exploration of the Swan River, G.F. Moore recorded that he saw axe marks on a tree left by Irwin’s party in 1831 (see below). While the native’s identification of Irwin can relied upon (given their ability to recognise faces and Irwin’s stature in the colony) the year stated (1831) is more problematic. It unlikely that Irwin made two trips to the same location that were both missed.
No reference is provided in Volume 1 to substantiate the dates of Dale’s April 1830 trip but assuming they are correct there wasn’t much left of April for another exploration to occur. Rank prevails and the title of Exploration Number 1830/97 has been changed to Captain Irwin’s expedition to trace the Swan River, 7-22 April 1830.
Exploration Number 1830/212
Robert Dale’s expedition to explore the ‘interior of this Country to the Eastward of Darling Mountains. 4 August 1830
Continuing our course due East, we obtained a view of the valley of the Swan, and could discern beneath us through the trees, that river falling over a bed of rocks – on descending I recognised it to be a waterfall which I had passed when accompanying Captn Irwin on an expedition into the interior in April last – quitting this and proceeding a little to the Southward of East, we in three miles again came to that river and continued along its left bank till we arrived at the termination of Captn Irwin’s journey, where he had left a Depot of provisions – we had the satisfaction of finding them uninjured – as we had had a journey of 12 miles this morning, I determined to rest here the remainder of the day to refresh the horses.
Exploration Number 1834/24
Mr G.F. Moores Report of an Excursion to trace the Swan River to its junction with the Avon River – 24 January 1834
It was near this that, whilst observing a tree of that wood which has the scent of raspberries, growing on a picturesque knoll, which overlooked the river, we were surprised by finding that one limb had been cut off by an axe, & two branches had been fixed across, evidently for the purpose of either marking the spot, or of arresting the attention. I have, since our return, learned from one of the natives that this was done by Capt Irwin, who went so far up the valley in 1831. He did not see any natives at that time, & the circumstance of their having observed so close as to recognise him afterwards, shews with what jealousy they watch the steps of the intrude
Shoobert J. (Principal Editor), Western Australian Exploration Volume One December 1826 –December 1835, Hesperian Press, Carlisle, 2005, pp. 158, 164, 343.