Remember Deep Throat (Mark Felt)? He basically spilled the beans on Nixon and Watergate because he was p***ed off about being passed over for promotion to the top job. But he couldn't bring himself to admit as much until he was ready to meet his maker.
For years, he preferred the speculation that he did it out of honor rather than a petty desire for revenge. Millions of people in Cambodia, Vietnam and Laos died or served in labor camps to massage his bruised ego. He was a true metaphor for the Washington swamp.
ODESSA probably got to it long ago. Or sold the location to someone else who excavated it.