In addition to its proximity to refineries in Illinois, Kansas and Oklahoma, the state of Missouri "is served by numerous pipelines carrying petroleum products," said Michael Right, spokesman for AAA in Missouri. He said it helps that Missouri has no sales tax on gas and also charges a relatively low gasoline tax of 17 cents per gallon.
The last time statewide average prices were below $3 per gallon was on Feb. 7.
After that, prices climbed from worries over the war in Syria and unrest in Egypt. More recently, there's been relative calm in the Middle east.