The Highland Archive Service is responsible for locating, preserving and making accessible archives relating to all aspects of the history of the geographical area of the Highlands. It provides four archive centres, the Highland Archive and Registration Centre in Inverness; the Caithness Archive Centre in Wick; the Skye and Lochalsh Archive Centre in Portree; and the Lochaber Archive Centre in Fort William. An archive service booklet is available online.
Clan Donald Library at Armadale Castle on the Isle of Skye has archive collections, with the main collection being Lord Macdonald's estate papers c1500-1948. They also have all the usual genealogy sources (census, OPRs etc) plus very good secondary sources.