You'd be surprised. My family is all from Nodak, they are prepared, they all know it won't last forever. North Dakota has seen numerous oils booms and busts over the the last 100 years. This isn't the first, and it probably isn't even the last. There was a HUGE boom in the 50s too.

http://www.ndenergyforum.com/topics/north-dakota-oil-and-gas-history

North Dakota's energy economy changed forever on April 4th, 1951, when drillers from the Amerada Oil Company struck oil in eastern Williams County near Tioga. Since this discovery, more than 13,000 wells have been drilled, resulting in the production of more than 1.3 billion barrels of oil.

13,000 wells for that boom. Currently the Bakken play is getting close to 8,000 wells, with the total field end-game to look like 35,000 - 50,000 wells. So this will certainly be the biggest boom North Dakota has ever seen. Each well is expected to produce for 45-50 years, with declining numbers starting about 30 years or so into production. The state of North Dakota is putting a good chunk of the taxes gained into a trust fund for future use, and to protect the money from spending it willy-nilly now.

A lot of my family lives in a small town in the Williston basin area, smack dab in prime Bakken territory. We have oil wells on old family farm land that we retained the mineral rights to, but no one has changed their spending habits, no one in the town has, except for maybe some new pickups. Well, my aunt bought a new Subaru Outback... woah woah big spender oil tycoon! They just appreciate the extra money while it's here. And that's a very common sentiment from the towns people. Even the people who don't have wells still have extra work, higher wages, more business for their companies and shops, etc.

Everyone in the little town they live in appreciates the extra business, the extra high wages, and the influx of people... but when they are all gone they will go right back to appreciating their little town and still live there. The people who came just for the oil work will leave. The companies that built up because of the boom will close any operations they had there. They will go back to knowing everyone in town, their crime rates will go back to nothing, and their roads will go back to only seeing a couple cars of people you know on them instead of truck after truck after truck.

North Dakota will always be an agriculture state, and part of the bread basket of the US. The oil is temporary, and everyone there knows that. Even the state knows it. The people are happy now, and they'll be just as happy after everyone picks up and leaves and they get their quiet state back. This isn't their first rodeo.