Write the Ohio River into your pages before Google has to guess
A metro spread across two states needs content that tells a searcher, and a search engine, which side of the river you actually build on.
Louisville sits in Kentucky. Jeffersonville, New Albany and Clarksville sit in Indiana, close enough that a homeowner there considers themselves part of the same market. A builder ranking across all of it is fielding inquiries under two sets of state rules. Requirements generally differ by state and are worth confirming with the local building department, your insurer or your own counsel.
Build two service area trees rather than one. A Kentucky tree covering Jefferson County, Oldham County and Bullitt County. An Indiana tree covering Clark County and Floyd County, naming Jeffersonville, New Albany and Clarksville by name. Each written in the vocabulary of that side, each honest about what you do and do not take on there.
A single page listing forty towns is the version most sites have. It ranks for nothing and reassures nobody. A homeowner in New Albany reading a page that mentions Floyd County twice will call. The same homeowner reading a comma separated list will keep looking.
If you only hold a Kentucky registration, say so on the site. Saying which side of the river you cover converts better than implying both and disappointing half the people who call.