Name : Lawrence R. Wiencke E-mail : wiencke@cosmic.utah.edu TITLE : The High Resolution Fly's Eye Experiment ABSTRACT : The High Resolution Fly's Eye measures light produced by high energy air-showers in the atmosphere. Above the predicted GZK cutoff the aperture of this instument approaches 10,000 km^2sr. This talk reviews the technique, and this experiment. Stereo observations of air showers will also be discussed.