Deadlifts stimulate the whole back, but target the lower back the most and you'll be able to handle heavy poundages by using correct deadlidt form. (fitnessandpower.com)
Using it with proper form should allow you to pull some seriously heavy poundages after a year or two of training. (fitnessandpower.com)
Keep using progressively heavier poundages each week to keep your muscles growing. (ironmanmagazine.com)