https://www.thedrive.com/the-war-zone/29101/whats-the-deal-with-army-helicopters-flying-a-secret-new-mission-over-the-capital

On top of that, the 12th has a far less well-known mission as part of the U.S. government's extensive "continuity of government" planning to keep running in the event of a major disaster, widespread enemy attack, or other crises. In such a scenario, the battalion would help fly top lawmakers and other senior U.S. government officials to secure sites, including Camp David, Mount Weather, and Raven Rock.