So we now know that The War Z only has one map, despite Hammerpoint having initially advertised multiple maps of between 100 and 400 square kilometres each. That's fine, a misunderstanding that's been corrected. The store page now correctly lists just one map, Colorado, though Hammerpoint still claim that it's 100 square kilometres in area. It certainly doesn't feel that big, so it's probably wise to check.
Would you like to know how big The War Z's map really is? 50 square kilometres? 75 square kilometres?