Interesting, i would have thought Alaska would be up there too...
With the punitive profit tax plan (ACES) put in place several years ago, the investment into Alaska was cut way back. While many of the US oil producing states grew their production rate, Alaska continued in decline. Even California made some slight gains in the same time period.
They finally repealed that mess and the companies have begun investing more. But it will take time to slow then stop the decline.