I was over a couple of years ago and everyone was complaining like hell that it had reached $2.70 per gallon. Taking into account their smaller gallon and approximate exchange rate, that works out at about 48p per litre.
They could not believe it when I told them that we had to pay the equivalent of nearly $8 per gallon over here.
A gallon of gas is pushing $4.00 a gal as of today. I think the average across the country is listed at $3.85. Due to bad weather where the manufacturing plants are located and a recent fire in another, the price will probably stay this high for awhile.
This is probably too late, but we returned today. The best we paid was $3.41 and the most was $3.66, strangely, the prices in the more touristy areas can be the least, the $3.41 was near the entrance to the Rocky Mountain National Park. Safeways were a good bet or Vallero (think that's it).