Forty-nine people — including three generations of the same family — were busted as part of a major heroin take-down in Westchester County dubbed “Operation Red Smiley,” New Rochelle police said Tuesday.

Two kilos of heroin were seized during the lengthy operation, which began when cops last year noticed that heroin stamped with a red smiley face was being circulated throughout their city and other parts of Westchester County.

Police said among those charged with running the drug ring are 70-year-old Jeffrey “Pop” Brickle Sr. and his grandson Jeffrey “Gunnar” Brickle, 31. Also arrested were Gunnar’s uncle, Jermaine Brickle, as well as at least four other members of the Brickle clan.

The investigation stretched throughout Westchester and into the Bronx and Pennsylvania, with the first arrests made in February and more busts coming as search warrants were executed in July and this week. Another 27 suspects were arrested on Tuesday — though one remains on the loose.

The charges range from misdemeanor drug possession to criminal sale of a controlled substance, police said in a statement.