We have enough OIL SHALE in the USA to keep us running for about the next 1,000 years. WHY aren't we using it?

The bulk of it is in Colorado, and Big Oil said in the 1980s (when oil was around only $20 or so per barrel) that once the price reached $60 or so, it would be economical for us to start gleaning and refining it. So by NOW, we could be making ourselves TOTALLY independent of foreign oil. So NOW what is Bush's, and Big Oil's, excuse for not doing that?