Abstract: A material collection system sensor includes an ultrasonic sensor mounted in a collection container above a discharge chute from a lawn and garden tractor mower deck. The ultrasonic sensor provides data to an electronic control unit representing the distance between a material pile in the collection container and the ultrasonic sensor. The electronic control unit filters out data that fails to meet certain pre-specified criteria and correlates the distance data to a fill level of the collection container. A fill level indicator such as a visual display is connected to the electronic control unit and displays information about any fill level of the collection container.