I understand what you are saying about the drop down arrows not being visible, but maybe you place a light yellow fill on the cell and inform user, "Use the light yellow filled cells".

As far as updating the values, you can make those ranges dynamic so if you entered Utah underneath California, the named range woould automatically be updated.

In regards to a pivot table, it could work, but in the end, you still have to instruct user how to interact with it.

Let us know what else we can help with