Why is North Dakota doing so well?

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.