dependent data validation drop down list

I have a data entry cell in a sheet asking for the users location (state). If the state entered is Wisconsin (WI), I want the next data entry cell to be a drop down menu with all of Wisconsin's counties listed. If the state selected is NOT Wisconsin, I want that data entry cell to accept any entry...and NOT be a drop down menu. Is this possible? If so, how can I make this happen?

I have already set up the state drop down list and formatted those cells as a named table. Same with the WI Counties. I just don't know if or how I can get the County data entry cell to become a drop down menu if WI is selected and have no data validation rules if any other state is selected.

Thanks!

Please see yellow banner on how to post a sample workbook.

adjacent to each county you will have to have the state in the left hand column.
give us a workbook laid out like that and it is relatively simple to have dependent dropdowns