A mobile machine includes a frame, and a set of wheels supporting the frame. The mobile machine also includes a set of ground-engaging tools mounted to the frame that are movable relative to the wheels to change a depth of engagement of the ground engaging-tools with ground over which the mobile machine travels. A first sensor senses a position of the frame relative to the ground surface over which the mobile machine is traveling. A second sensor senses a position of the frame relative to the wheels. The sensor signals from both sensors are used to control the frame height.
