You're in a lower cost-of-living location, and one where there's less competition; employers don't pay as much there because they don't have to. That said, if you like where you are, you might start by looking for remote work that pays better (from companies that don't say "we can pay you half as much because you're not in California").

Also, look for employers that have a robust technical job ladder for advancement; that's part of how you get a salary like that, and even higher. (I know software architects making 7-figure salaries.)