One of the items that has come up in the debate over energy policy in the Congress is the idea of getting fuel out of rocks in the west of the United States.
The issue is most commonly referred to "oil shale," which has always been a somewhat expensive plan to get fuel from sedimentary deposits.
"When the price of shale oil is comparable to that of crude oil because of diminishing resources of crude, then shale oil may find a place in the world fossil energy mix," says the web site of the American Association of Petroleum Geologists, which is based in Tulsa, Oklahoma.
Some see that happening, now that oil is well above $100/barrel, with many wondering whether it is going to hit $200/barrel.
But in a recent hearing in the Congress, Energy Department officials who were quizzed about the issue sort of threw a wet blanket on the thought that oil shale was going to become a major replacement for imported oil.
"The economics of oil shale, even at these prices, are still relatively unfavorable," testified Guy Caruso, who heads the Energy Information Administration.
That was protested sternly by Sen. Wayne Allard (R-CO) who comes from a state where some federal oil shale leases were acted on during the 1970s. But since then, little progress has been made.
One major hurdle for oil shale development is that it requires water for processing, and obviously, water is not a never-ending resource in the West. Environmental groups have been pressing that argument for years and I wouldn't expect that to evaporate now.
President Bush has joined Republicans in the Congress in calling for legislation that would open up new leasing possibilities, but Democrats have been cool to the idea.