There's a group up in the Bangor area who every 2-3 months or so runs a multi-game tournament that usually features Smash in some capacity (Melee, Sm4sh, and PM are the ones they typically run). They also run SF4, Injustice, and a few others as well. They don't always run their events in Bangor (sometimes Waterville, one time as far south as Biddeford), but that's their home area. They're on Facebook as a group named "The Maine Fighting Gamers Alliance".
That's about all I know as far as Maine tournaments go. I think there's a weekly or two in Portland, but it's more practice and less tournament. New Hampshire (closer than MA, at least) just started running a PM weekly on Sunday, too.