Proof is in the people who said what happened there, because they were there... And i seriously doubt that entire town is delussional or crazy. Even so the spy ballon story again came from US gov. why? Because those people begun to make impact of events that happened there so gov. needed a more reliable, buyable story...
And if i worked in gov. i would probably make the same thing, cover up, research, investigate and keep it for myself and others who participated in that event

. Those were cold war times so information was everything...You wouldnt go public saying,"Hey we just got some alien technology parts and were gonna use'em for our own good against Soviets if they would do any daring moves..."
Sorry for english typed really fast.