I know of two Mckellar families in Sanilac County, both from the same place originally and connected by marriage as well.The "Gore" McKellars, John McKellar and wife Catherine McNeil, emmigrated to Omard, Flynn township in 1876 from Mosa twp, Middlesex County, ONT.They brought with them their 12 grown children; some with spouses, as well as John's widowed sister Mary McKellar Campbell and her children. Also John's brother Donald and family, as well as some Graham and McAlpine in-laws.All settled in Sanilac, though some soon moved on to Detroit.
A branch of the "Bear Creek" MacKellars, also of Middlesex County, Ont.,Donald Black McKellar andwife Mary Black, arrived in Yale, Michigan, in St. Clair County in 1879 and established a Disciples of Christ Church, which I believe is still going.Later moved to Speaker twp, Sanilac, where D.B.also preached.Donald and Mary had 14 children, all born in Mosa.I believe all but 3 of the children came to Michigan.
Both of these families descended from Scots immigrants to Ontario originally from Argyll, scotland.They reconnected with the marriage of John and Catherine's son Peter to Donald and Mary's daughter Mary in 1892.
I believe Donald and Mary are buried at Elmwood Cemetery, Yale.The entire family of John and Catherine is buried at Omard, except for the youngest daughter, Flora McKellar Hands, who lies in Elk Cemetery at Peck.
I have much more on the GoreMacKellars, including photographs.Please contact me directly.