The Indiana Chamber gave credit to North Dakota for doing so well economically, especially compared to other states in the region.  A quote from the web site:

Compare Indiana’s state budget to our Midwest neighbors and we’re doing pretty well.

But we’re not able to match an unlikely leader in economic prowess – North Dakota. Oil deposits, heavy agricultural interests and even its location near Canada are factors in producing a large budget surplus.

Included was a link to this article, which details how and why North Dakota’s economy is so strong right now.