Where does eastern time zone change in indiana?

Under federal law, 82 Indiana counties are in the Eastern Time Zone and 10 are in the Central Time Zone. The counties in the central time zone include five in the northwest (Lake, Porter, La Porte, Newton and Jasper) and five in the southwest (Posey, Vanderburgh, Warrick, Spencer and Gibson). Neighboring States observe both Eastern and Central Time. Illinois and western Kentucky observe central time, while eastern Kentucky, Ohio and the part of Michigan adjoining Indiana observe Eastern Time.

Most of the speakers and non-speakers who filled out the speakers' registration cards (but left before they were called) expressed their view that Indiana should be in the same time zone, preferring central time, a result incompatible with Indiana Law and the DOT's notice of the proposed regulation.