The more we look for oil and natural gas in the United States, the more we find. If only we were allowed to go and get it.

According to the Department of the Interior (DOI), huge onshore deposits of energy can be found on federal lands. Yet much of this energy is either explicitly off-limits or hampered by regulatory constraints that effectively make it so. Part of the solution to high oil and natural gas prices lies right under our feet, but Congress won't change the laws that keep this domestic energy locked up.

Federal lands are critical to the energy policy debate because most of America's onshore energy is located in the West and in Alaska, where more than half the land is under federal control. Such lands, DOI estimates, "contain 31 billion barrels of oil and 231 trillion cubic feet of natural gas." Thirty-one billion barrels of oil represents 50 years of current imports from Saudi Arabia and 231 trillion cubic feet of natural gas is enough to supply all of America's households for 46 years.

However, "just 8 percent of onshore Federal oil and 10 percent of onshore Federal gas are accessible under standards lease terms," DOI notes. The rest is either restricted outright or subject to considerable amounts of red tape. Among the former: Alaska's Arctic National Wildlife Refuge, where an estimated 10 billion barrels of oil lies beneath a few thousand acres at the edge of this nearly 20 million acre refuge.

Granted, few Americans want unrestricted oil and natural gas wells in our treasured National Parks or other areas of scenic, environmental or historical significance. However, the drilling restrictions on federal land far surpass such reasonable limits. This is especially true given the advances in drilling technology that have dramatically reduced both the above-ground environmental footprint and the risk of spills.

Even more energy lies offshore. Some 86 billion barrels of oil and 420 trillion cubic feet of natural gas are beneath America's waters, DOI says. Of those amounts, 19.1 billion barrels of oil and 83.9 trillion cubic feet of gas lie in federally-controlled territorial waters that are completely off-limits to leasing and development.

The actual volumes of onshore and offshore energy could be far greater - DOI's initial energy estimates tend to be low. This is especially true of the off-limits areas, which haven't been thoroughly explored.

Many anti-energy activists and politicians insist that America's untapped oil and gas reserves are merely a "drop in the bucket" and therefore not worth the bother. But these DOI estimates put the lie to this claim. As Congress once again addresses energy issues, it shouldn't ignore the significant amount of energy right here in America. It's time to make this energy available to the American people.

Ben Lieberman is a senior policy analyst in the Roe Institute for Economic Policy Studies at The Heritage Foundation.