Cheap gasoline is getting easier and easier to find elsewhere as well, with about one gas station out of every six nationwide now offering a gallon of regular for less than $2, according to GasBuddy.com.

But cheap gas isn't limited to Missouri. There are six other states with statewide averages within a dime of the $2 mark.

Gasoline dropped to $2.09 a gallon in Parkersburg, but in Charleston and many other WV locations, the price was about $2.45 a gallon.

The plunge in oil prices is what's taking gas prices lower.

The various types of crude have fallen by nearly 50% since the highs of earlier this year.

Oil rich states are taking a hit with their tax revenues.

The US, in recent years, has become independent with oil and natural gas production.