The first The War Z map is Colorado, which is a huge 200km map. It will include many urban and city environments for players to try and survive from the unending horde of the undead.
The storyline so far is that the virus infected 95% of the population 5 years before the player is in the world. The military tried to contain the virus in its' early stages but to little success. You will be able to find evidence of futile attempts at stopping the virus while travelling around Colorado.
Colorado will have several Safe Settlements. These settlements will offer a hub for players to exchange Loot such as Weapons and Consumables. The Marketplace will also be available in order for players to use Currency. Finally, these settlements will be where players come to take part in Social Rewards such as the Bounty Board.