Hell on Earth: After Doomsday
Denver is the home of the Combine.
The city itself is surprisingly intact, having been hit on Judgment Day by high air-burst neutron bombs which did little structural damage, followed by a fast-moving, highly lethal virus which killed 98% of its victims. With 99% of the population dead within days of the end of the world, wide-scale looting didn’t occur, so aside from the ravages of time and the Black Hats, the city is a treasure trove waiting to be looted.
Unfortunately, there’s a little thing called the Combine in town.