The Energy Task Force convened by Vice President Dick Cheney in 2001 called for expanded production on federal lands and offshore; these figures, drawn from the data of the federal Minerals Management Service and analyzed by the Environmental Working Group, a research and advocacy organization based in Washington, give a partial sense of how the task force’s priorities have been carried out, and to what effect.  “You have to start with the recognition that most wells drilled in the Rockies are not oil wells — they are gas wells,” said Porter Bennett, the president and chief executive of Bentek Energy, one of the industry’s largest research firms. “There would never be an expectation of huge returns on the oil side,” he added.  Dusty Horwitt, a senior analyst for public lands at the Environmental Working Group, said that opening more lands to drilling would not bring down the price of natural gas. “We’ve turned our Western lands into a pincushion and gasoline is $4 a gallon and the price of natural gas has gone through the roof,” he said. “What these data show is that conservation and renewable energy are likely to be the solution to our energy woes.”  Mr. Horwitt added, “On the oil side, the data show that there’s just not that much oil out there in the West.”  More of the nation’s oil reserves are located in Texas (23 percent), offshore (19 percent), Alaska (18 percent) or California (16 percent), according to the federal Energy Information Administration. And the biggest onshore discoveries — like the Bakken field in western North Dakota and eastern Montana — are mostly not under federal land.  Last month, Mr. Bush lifted the executive prohibitions on drilling on the outer continental shelf, urging Congress to rescind its ban as well. For the last three years, offshore wells have supplied about 32 percent of the nation’s total oil production.  However modest the Rockies’ contribution may be, they are the place where the impact of the rapid expansion of energy drilling infrastructure can best be measured, both in terms of energy production and environmental impacts.  Colorado, New Mexico, Utah and Wyoming together contain about 10 percent of the nation’s oil reserves and about 30 percent of natural gas reserves. About 90 percent of onshore federal drilling permits were issued there in the 2007 fiscal year, according to federal public lands data analyzed by the Wilderness Society.  The environmental effects have been palpable. The expansion of the energy industry has subdivided parts of western Wyoming and western Colorado into a rabbit warren of wellheads and roads. The Pinedale, Wyo., area had its first ozone alerts last winter, thanks to a combination of factors: natural gas flaring from scores of wells, increased vehicle traffic associated with drilling activities and seasonal temperature inversions. One study showed that the mule deer herd that migrates near Pinedale declined by nearly half from 2000 to 2005.  Brian A. Rutledge, the executive director of Audubon Wyoming, said that in energy-drilling areas around the state sage grouse populations had declined by more than 80 percent in the last seven years.  Industry representatives and their Republican supporters in Congress argue that companies do observe environmental safeguards, like closing some areas to drilling seasonally to protect wildlife. Environmental concerns, environmental reviews and lawsuits can hold up drilling five to eight years after a lease has been awarded, they say.  “If you restrict drilling,” said Mr. Bennett of Bentek, “you’ll go from a situation where we’re growing one billion cubic feet in production a day to a situation where you’re flat or declining in two years” — as happened in the Powder River basin six years ago after environmental restrictions tightened.  Industry representatives argue that the high prices, and the technical skills learned in recovering hard-to-retrieve oil in places like Texas, provide an opportunity to find oil and natural gas that would not have seemed worth the trouble a few years ago.  Marc Smith, the executive director of the Independent Petroleum Association of the Mountain States, said that in the last six years more than $20 billion had been invested in his region to increase energy production.  “Because we are a frontier region,” Mr. Smith said, “it’s heavier lifting to build the infrastructure to ship energy from where it’s produced to where it’s needed.”  Also, Pete Stark, of the energy analysis firm IHS, said: “It takes an increasing number of wells to be drilled each year to replace lost production. The industry is running very hard just to stay in place.”  But for all this activity, the Wilderness Society says, in a state like Colorado, where 4.9 million acres are leased out, just 1.4 million acres are under production. And of 7,124 drilling permits approved on public lands in fiscal year 2007, only 5,343 wells were drilled. Whether the cause of the lag time between leasing federal lands and producing oil and natural gas is due to environmental restrictions or strategy by energy companies, the delays mean that “opening protected areas of the coasts or public lands to new leasing is not going to lower the price of gasoline,” said David Alberswerth, a senior policy adviser at the Wilderness Society.  But Richard Ranger, a senior policy adviser with the American Petroleum Institute, takes the long view.  “There is obviously in the Rockies a tremendous amount of industry investment,” he said. “It is reasonable to expect that surge will bear fruit with new production over the coming decade.”  A version of this article appears in print on , on Page A15 of the New York edition with the headline: A Push to Wrest More Oil From Land, but Most New Wells Are for Natural Gas. Order Reprints| Today's Paper|Subscribe
While those hoping to lower prices at the pump are clamoring for new oil, most of the new onshore drilling of the past seven years has produced natural gas, not oil.