Much public land exploration is on hold
More than half the federally owned land approved for oil exploration and leased to energy firms for that purpose is going unexploited - because the companies holding the rights say it would be economically infeasible.
175 million barrels of oil lie under federally owned land. 70 percent of that land has been approved for exploration and drilling. But 56 percent of it goes untapped. Offshore exploration is even more modest, with 72 percent of the area leased to energy interests not producing oil.
The Congressional Budget Office says the leaseholders are waiting until oil production becomes more profitable.
In the meantime, the government makes a profit on the leases whether or not the energy companies act. Today's slideshow reveals how much - and more.
View the slideshow here.