Abstract: A guide system for planning missions of autonomous or semi-autonomous material displacement machines includes an operator interface and at least one computer coupled with the operator interface. The at least one computer is structured to receive working elevation information associated with missions executed by machines and indicative of working elevation parameters dependent upon disposition of a material displaced by the machines. The guide system is further structured to receive surrounding terrain information and compare the working elevation parameters to a surrounding elevation parameter. The guide system produces elevation variance alerts based on the comparison, and displays the elevation variance alerts in an operator-perceptible form such as graphically on a display in an operator interface.