Urban Dictionary - "According to The Chicago Tribune, Lake County is a included in the Chicago Metropolitan Area, but the TRUE region is located only in the Northwest area of Lake County IN; consisting of Whiting, East Chicago, Hammond, Munster, Highland, Griffith, Gary, and the North sides of Dyer, Shererville, and Marrillville. The South sides of Dyer, Shererville, and Marrillville along with St. John, Crown Point, Hobart, and Lake Station (aka Snake Nation) are only considered Semi-Region (People from there can still consider themselves “regionites,” but must bow down to anyone from the TRUE region). People from Porter County, La Porte County, and Southern areas of Lake County such as Lowell, who tell people they are from the region and try to gain of the region’s mystique, are ABSOLUTLY NOT from the region. "
Wikipedia - "Northwest Indiana comprises Lake, Porter, LaPorte, Newton and Jasper counties in Indiana. This region neighbors Lake Michigan and is part of the Chicago metropolitan area. "