A ground contour sensing system and method for a vehicle with a mowing head. The system includes a sensor system that measures a ground contour in front of the mowing head, and generates contour measurement signals; and a controller that determines whether to move the mowing head based on the contour measurement signals, and generates movement commands for the mowing head when it determines to move the mowing head. The mowing head can include tilt and lift cylinders, and the controller can determine whether to move the mowing head using the tilt or lift cylinders. The sensor system can include a pivot arm that moves in response to changes in the ground contour, and an angle sensor that measures an angle of the pivot arm. There can be one or more sensor systems positioned between the right and left sides of the mowing head.