The one place in America where 3.1% unemployment looks like a problem

North Dakota, the epicenter of both the shale oil boom and bust, is starting to really feel the pain: the state’s unemployment rate hit 3.1% in March.

While that’s a jobless figure that would be the envy for most US states—the median state unemployment rate was 5.4% last month—unemployment in North Dakota is now the highest it’s been in more than two years, and a sign of the trouble that might be ahead as the oil layoffs keep coming.