Hiya jimjaqu,
Donald was from Altandhu in Coigach, up in the north-west third of Lochbroom Parish. His age in the 1861 census was 4, and in 1871 he was 14, occupation "hird", in 1881 he was 23, a fisherman. Interesting though that he does not appear in the IGI even though it includes the index to civil registration for that period....
His mother was from Polglass, the Coigach Stewarts all said to descend from four brothers who fled with their families as refugees following the Battle of Culloden.
His paternal grandmother was one of the large tribe of Reiff MacKenzies, there are many genealogists in the descent from that family, and through their shared research and my own there are almost 1,400 descendants traced through ten generations. If you descend from Donald I'd be happy to share their tree.
Murdo MacKenzie from Reiff born 1853, a second cousin of Donald, also worked at the Inverness Asylum, as did his wife and several of their sons.
All the best,
Donald.