One way to find matches is to go to one of the major sanctioning body web sites and find the clubs in your area, that do their matches - uspas.com, idpa.com, icore.com, steel challenge, 'etc.
Then go to those club web sites that are near you, and look for all the kinds of matches they do.
If any have 3 gun matches, they will be listed, usually under events or matches or something similar.
