Much of the most promising American oil lands have been declared off limits for oil drilling and production for many years. This has cost us all lots of money at the gasoline pump, but the effects elsewhere may be even bigger. The office of US Rep. John E. Peterson has prepared an estimate of the royalties (which means government revenues that wouldn't come from individuals' taxes) that could be realized, and arrives at the astonishing figure of 2.5 trillion dollars.