Yes, Riggs is an Associated Family of the House of Boyd, aka, "Clan" Boyd.
Yes, Riggs descendants are entitled to wear either of the Boyd Tartans... Ancient or Modern. Additionally, you may also wear the Ayrshire District Tartan, or the Stewart Hunting Tartan, which is the National Tartan of Scotland..
To wear the tartan of a clan/house is to also show your allegience to the Chief of Name of that Family.
If you will contact me directly with your location or travel plans, I will provide you information regarding the events near you. Should we not have a tent at the event near you, we do have relationships with other clans who would extend their hospitality to you. Clan Cian, Clan Stewart, Clan Wallace and others.
Unfortunately the MacLachlan site that had the best games listing was transferred to COSCA and they have been unable to get the site up and running so far this year. Clan MacLachlan Western Branch and the Scottish Information Society are working toward rebuilding a strong games listing.
We thank you for your interest and look forward to seeing you at the games!
Lauren M. Boyd, FSA Scot
House of Boyd Society, Inc. aka Clan Boyd (since 1988)http://www.clanboyd.ORG
-- Official Website for the Clanpresident@clanboyd.org
President, Scottish Information Society