Abstract: A self-propelled combine has a forward, vertically adjustable feeder house carrying a transversely elongated harvesting platform at its forward end. A flexible cutter bar is mounted on the leading lower edge of the platform by a plurality of transversely spaced independently vertically adjustable arms that permit different areas of the cutter bar to adjust independently of the other areas so that the cutter bar is free to follow the contour of the ground. A transverse rockshaft is journaled on the platform rearwardly of the cutter bar and has a plurality of radial feeler arms that engage the respective cutter bar mounting arms, so that as the mounting arms swing upwardly, the rockshaft rotates to a position that corresponds to the uppermost arm. One end of the rockshaft is connected by a suitable linkage to the movable element of an indicator at the side of the platform to give the operator a visual indication of the position of the uppermost area of the cutter bar.