Do you have the 1881 families for Latheron? There are lots of Alexander Sutherlands (160 born in Caithness). Very possibly they are all related.
Let me know and I'll post them.
Is this your one?
Dwelling: Upper Lybster
Census Place: Latheron, Caithness, Scotland
Source: FHL Film 0203401 GRO Ref Volume 038 EnumDist 5 Page 13
Alexander SUTHERLAND M 74 M Latheron, Caithness
Margaret SUTHERLAND M 72 F Latheron, Caithness
Occ: Wife Of Crofter
Catherine SUTHERLAND U 41 F Latheron, Caithness
Occ: Dom Serv
John SUTHERLAND 9 M Latheron, Caithness
Rel: G Son
Margaret SUTHERLAND 8 F Latheron, Caithness
Rel: G Daur
Emelia BAIN W 70 F Latheron, Caithness
Rel: Lodger Handicap: Blind
If this is your family then I truly recommend you go onto http://www.scotlandspeople.gov.uk/
As you will find the deaths of both Alexander and Margaret which may open up other generations.
All the best,