Californians have been paying nearly $6 a gallon. See why prices are so high, how they compare historically, and how Trump's Iran blockade fits in.

Average gas prices in the United States hit $4.18 on Tuesday, their highest level since the Iran conflict started, as peace talks stalled again.

Californians have been paying nearly $6 a gallon. See why prices are so high, how they compare historically, and how Trump's Iran blockade fits in.