We have access to the Canadian/Alaskan oil field, part of which is under the ANWR. That field is larger than the Middle East.
By the way, the accessible oil in the Continental US is half the size of the Middle East fields.
Got a source?
Everything that I've read says we have about 21 billion barrels of oil reserves in the US. Just Saudi Arabia has about 267 billion. Add in Iraq, Kuwait, and UAE, you're looking at 787 billion barrels of oil.
(This is from your wikipedia link on "oil reserves", by the way).
You should read different sources, the USGS estimates that we have 50 billion bbs of producible reserves, and that estimate is from before they had the modern methods, so the estimate is low. The USGS seems to have a history of low balling estimates, they underestimated the oil in the Bakken reserve in North Dakota by a factor of 25.
I pointed out Wikipedia as a place to start because Care was completely unable to find any information about oil in the ground. If you stop there you will never learn anything.
Your numbers are wrong. This is the USGS report, from 2008 (there have been no new advances in oil extraction methods in the last 2 years).
USGS Release: 3 to 4.3 Billion Barrels of Technically Recoverable Oil Assessed in North Dakota and Montana’s Bakken Formation25 Times More Than 1995 Estimate (4/10/2008 2:25:36 PM)
3 to 4 billion bbls. Not "500 billion", like jroc said, or "50 billion" like you said.