Donald the Beaver is my 1st cousin 4 x removed.
The Book Butternuts and Maple Sugar by Elsie MacMillan pg 279 (book can be found and read on-line)
Donald the Beaver MacMillan born Apr 24 1804 died Apr 21 1897 married Mary MacMillan They lived as you said on 34.7 Lochiel Glengarry
Donald and Mary had 11 children according to the book.
Donald the Beaver was born in Upper Canada. It was his father Archibald and his brother Ewan (whom I descend from) that emigrated from Ardnamurachan Scotland in 1790.