Alaska has huge oil and natural gas resources. However, these guys are totally incorrect.
The US absolutely does not have more reserves than Saudi Arabia. That country and Iraq collectively are the top two largest reserves in the world. Lucky, really, because basically nothing else of value comes out of that desert anymore.
The government's not attempting to 'cover up' anything. They simply don't want to tap those reserves, in case OPEC decides to truly fuck us over. In light of current politics, I can't say I blame them.