Gasoline prices dropped below $2 across most of the nation early in the year when crude dropped to $30 a barrel. In some isolated cities, the price fell to very close to $1. The pendulum has swung the other way, as oil has moved above $45. Gas prices have risen very close to $3 for a gallon of regular in several of California’s largest cities.

The average price for a gallon of regular across the country is $2.21. That is up from $2.04 a month ago.

In San Francisco, prices already have risen to $2.97, and they rise most days. A modest number of stations already charge over $3. The high price probably has to do with the state’s high gas taxes, and the fact that San Francisco is not close to any huge refineries, which means transportation cost becomes an important factor.

Most of the other California cities with high prices are on the Pacific Coast or nearby. The average price in wealthy Santa Barbara is $2.85, in Los Angeles also $2.85, in San Jose $2.84, and $2.82 in Ventura, Oakland, Salinas and Orange County.

At the other end of the price spectrum are cities in several oil-rich states, or ones close to refineries. The price is well below $2 in a number of cities, mostly in Oklahoma, Texas and Missouri. The total count of the major cities in these states that have a price below this level is 19. The lowest among them are in Kansas City, Mo., where the average price is only $1.88.

And the final disadvantage for California drivers is the level of the state’s gas taxes and levies, which stand at $0.5883 per gallon, against a national average of $0.4804. The state with the lowest taxes is Alaska at $0.3065, according to the American Petroleum Institute.

The price of oil will always be the largest component of gas prices. Crude prices increased 50% in a relatively brief period. As hope falters there will be an agreement among large oil-exporting countries that would drop production below current levels, gas prices in more of California will be $3 soon.