The end of the Democratic primary sea son wasn’t the only big happening in South Dakota last week.

The other news comes from tiny Union County, where voters approved a proposal holding promise for America’s energy supply.

Residents OK’d a zoning ordinance to let Hyperion Energy build the nation’s first new oil refinery in more than three decades. The company hopes to use the site to process some 400,000 barrels a day of Canadian tar-shale oil.

That’s great news. America’s dearth of refining capacity is a major cause of the country’s sky-high gasoline prices.

Gas prices spiked more than 45 cents a gallon, for instance, when Hurricane Katrina took out a full fifth of the nation’s refining capacity in a single day.

But environmental and not-in-my-backyard opposition has effectively torpedoed every attempt to build new capacity – which is what makes Union County’s vote so heartening.

Clearly, residents liked the prospect of nearly 2,000 permanent, high-paying jobs.

The Hyperion proposal still has hoops to jump through – but the fact that it’s gotten this far suggests a return to sanity in America’s energy debate.