I looked into the North Dakota State Bank and didn’t see any reason that would make much of a difference, so I check out their ‘export’ industries:

https://www.dmr.nd.gov/oilgas/stats/DailyProdPrice.pdf

https://www.dmr.nd.gov/oilgas/stats/gasprodsoldchart.pdf

https://www.dmr.nd.gov/oilgas/stats/DrillStats.pdf

all found here:

https://www.dmr.nd.gov/oilgas/

And all with under 500,000 people.