That map accounts for even smallest presences so you might not want to believe all it says (piromalli in Philadelphia was a one off)

The Siderno group has had and still have important connections in NYC where it had a presence since 1970s. With the sidernesi come a number of satellite clans, like the Aquino/Schirripa you see there). Currently ndrangheta surnames (which might or not mean ndrangheta full association) are in the Gambino family and also, as said above, for business with Genovese.

The strongest link remains through Canada and the sidernesi. In any case Camorra wise, these are very very very remote presences, that map considers Camorra presence when there is one person loosely associated with a clan or loosely from Campania, the Camorra clans don’t have the kind of structure that can “migrate”, it is always a one off venture as they tend to associate with others abroad