Nothing is safe from sudoku, not even Great Ol' America. Every state including Washington DC must be filled with the numbers 1 through 12, however, states that border each other or states that are seperated by one state cannot contain the same digit.
Legend
Colored state borders: Blue borders mean that the 2 bordering states differ by 1 Lime borders mean that the 2 bordering states differ by 2 Red borders mean that the 2 bordering states differ by 3 Magenta borders mean that the 2 bordering states are in a 1:2 or 2:1 ratio
Tripoints are the point where 3 state borders meet, but it also includes borders with the ocean/Canada/Mexico: Red tripoints contain the product of the 3 surrounding states Green tripoints contain the sum of the 1-3 surrounding states Blue tripoints contain the median of the 2-3 surrounding states
States that are colored: Yellow states are higher than all of their neighbors Orange states are lower than all of their neighbors
Not all possible border colors and state colors are given, i.e. a state that is higher than all of their neighbors can be white; it doesn't necessarily have to be yellow.
To select a state, use the up and down keys or the clickable table under the map. The current selected state is denoted by a "?". Enter the correct number in the textbox with your keyboard.
The 4 corner states border each other. The 9 tripoint in Washington DC does not include Virginia and Maryland.
Get some paper, because you're going to do a lot of guess-and-checking. Good luck!
Hint: Start at Washington and reverse manifest destiny
However, with pure logic I'm left with a group of 15 states for which another solution seems possible. More precisely, after all possible logical eliminations made: If MA was 4, solving from there in the order RI, CT, NY, PA, DE, MD, TN, MS, WV, OH, IN, NH, ME would all seem to work flawlessly and finally leaving VT with three equally possible numbers. I've double-triple-quadruple-checked all the colours, tripoints and neighbours' neighbours, but I fail to see any contradiction. Am I still missing some tiny detail? That's of course possible, it took me an eternity to realise DC was yellow!
GA 9, SC 5 and FL 8 wouldn't work because Missouri is also 9.
The DC/MD/VA circle is not a tripoint, it represents the number in the honorary state DC.
But the NY/PA/NJ seems like a silly mistake on my part.
DC has also been made into its map shape to help disambiguate
However, with pure logic I'm left with a group of 15 states for which another solution seems possible. More precisely, after all possible logical eliminations made: If MA was 4, solving from there in the order RI, CT, NY, PA, DE, MD, TN, MS, WV, OH, IN, NH, ME would all seem to work flawlessly and finally leaving VT with three equally possible numbers. I've double-triple-quadruple-checked all the colours, tripoints and neighbours' neighbours, but I fail to see any contradiction. Am I still missing some tiny detail? That's of course possible, it took me an eternity to realise DC was yellow!