The invention is a combination of a short ground sensor arm mounted close to the cutter bar and a longer rod mounted towards the rear of the header. The short front sensor and long rear sensor are connected by a linkage which translates motions from either sensor to the other sensor. A second linkage translates the motions of both sensors rearward to a protected area under the header which contains the potentiometer. This configuration transmits useful ground position signals to the header height controller in both low and high cutting heights. The invention advantageously reduces the likelihood of damage to the short front sensor when the machine is reversed since the longer rear sensor arm pulls the shorter forward sensor arm up by means of the linkage to a position where damage is unlikely.