Chesapeake Bay - massive crater

I'd never heard of this, but I was watching a show on the Discovery Channel talking about pre-historic North American animals. Apparently about 35 million years ago a massive impact crater was formed in the Chesapeake Bay area. The crater has subsequently been buried, but investigation is showing the crater to be at least 50-60 miles wide and a mile deep.

Here's a couple of LINKS
NATIONAL GEOGRAPHIC

WIKIPEDIA