My home state of Oregon mandates a minimum wage of $13.20 in rural areas and $15.45 in the Portland metro area, and it adjusts to inflation.
I was part of that! I was on a team that made a web site that visualized the effect on poverty levels on a county-by-county basis when the minimum wage was at different levels. It made the need for a split minimum wage obvious, since the minimum wage that is necessary for metro areas is inappropriate for rural areas. Rumor has it that the legislature used it in the decision making to some degree.