Automation of agricultural harvesting equipment in the near term appears both economically viable and technically feasible. This paper describes the Demeter system for automated harvesting. Demeter is a computer-controlled speedrowing machine, equipped with a pair of video cameras and a global positioning sensor for navigation. Demeter is capable of planning harvesting operations for an entire field, and then executing its plan by cutting crop rows, turning to cut successive rows, repositioning itself in the field, and detecting unexpected obstacles. In August of 1997, the Demeter system autonomously harvested 100 acres of alfalfa in a continuous run (excluding stops for refueling). During 1998, the Demeter system has harvested in excess of 120 acres of crop, cutting in both sudan and alfalfa fields.