With the price of gas hovering near $4.00 per gallon (still almost a buck more than a year ago, despite the recent retreat), most Californians are already in “station shock.”

But what does gas actually cost? There’s the price at the pump, sure, but what about the hidden costs of pollution in terms of health and the environment?

The Center for Investigative Reporting takes us along on the journey that a gallon of gas makes, from oil field to gas tan, keeping a tally along the way.

California Watch, at the Center for Investigative Reporting is a content partner of KQED and Climate Watch.