oil reserves united states

we have here in the united states the largest oil reserves. we have more than the whole world combined in terms of total reserves. the bakken formation has been confirmed that there may be as much as 5 billion barrels of recoverable oil in that region. before he died leigh price did some research in that region as well and there could be as much as 400 billion barrels of oil. gull island in alaska has a 200 year supply of oil and natural gas that we have yet to tap. also in colorado in the green river formation, there may be as much as 2 trillion barrels of untapped oil. as well as the rest of the united states. with technology being what it is today we can extract this oil for less than 20 dollars a barrel making us energy independent. instead of importing oil from other countries why not put some good old americans back to work and start extracting the oil for our uses and exporting it to other countries.