A wide area mower with an open-box structure mower deck. The deck has a width from the left to right side of about 72 to 120 inches. The deck's length is about 24 to 70 inches. A left and right front wheel are positioned in front of the deck. The wide mower deck will flex, twist, or bend when one of the left or right wheels travels over uneven terrain while the rest of the mower travels over substantially level terrain. A cutting height adjustment mechanism is provided on the mower that allows an operator to raise or lower an entire left side or an entire right side of the mower deck to a selected cutting height. This is done simply by disengaging a locking mechanism and manipulating a lever on a four-bar linkage attached to each side of the deck and then re-engaging the locking mechanism.