No need to sigh. USA has slightly more than 21 billions of barrels of proven reserves of oil (Wikipedia). Considering current consumption of 20 millions of barrels/day, These reserves would under ideal conditions be sufficient for roughly 3 years. There is of course the question of EROI, because you would have to invest in infrastructure to tap these reserves - because most of them are hard/dangerous to get, as the Gulf spill demonstrated. So that's it, 3 years. Is that "plenty of oil"?