After searching Youtube and the Wiki, I've decided I found a [disappointing] easter egg in Lonesome Road. As soon as you exit the first Hopeville Missile Silo, hug the left wall until you are behind an overturned bus. Behind the bus is a footlocker, a teddy bear holding a Bowie Knife, and 3 or 4 empty whiskey bottles. This is a nod to none other than Call of Duty! If you've played the Zombies mode, you'll know what I'm talking about.