Orkmont appears to be one of the smaller islands, if not the smallest, of the Iron Islands. The only member of the house mentioned is Lord Alyn Orkwood, the Orkwood of Orkmont.
Alyn Orkwood was present at the kingsmoot, and caught at the arm of the hornblower who collapsed after sounding the dragon horn of Euron Greyjoy. Orkwood is one of Euron’s earliest supporters in the Iron Islands following his return.