Abstract: A support system and height control mechanism for a flexible floating cutterbar to be used on a crop harvesting machine. The support system includes counterbalancing shoe support springs that are easily adjustable to regulate the lifting pressure for the cutterbar head by the use of a conventional tool. The height control mechanism is especially useful for the header of a machine having a flexible floating cutterbar mounted on the header where a cutterbar can follow the contour of the land wherein the highest point along the cutterbar is sensed and will control the height adjustment for the header. Sensor fingers along the bar back of the cutterbar are connected through a lost motion connection to a control for adjusting the height of the cutterbar in accordance with the contour of the land being harvested.