Gravity waves are important drivers of chemical species mixing, energy and momentum transfer into the MLT (~80 - 100 km) region. As part of a collaborative program involving instruments from several institutions Utah State University has operated a Mesospheric Temperature Mapper (MTM) at the new Andes Lidar Observatory (ALO) on Cerro Pachon (30.2°S, 70.7°W) Since August 2009. A primary goal of this program is to quantify the impact of mountain waves on the MLT region. The Andes region is an excellent natural laboratory for investigating gravity wave influences on the MLT region, especially the study of mountain waves, created by strong winds blowing in from the Pacific Ocean. Large amplitude mountain waves have been measured in the stratosphere on many occasions, however, their penetration into the mesosphere has only recently been recorded (Smith et. al., 2009). In this study we have used MTM image data in coordination with all sky imager, meteor wind radar and other wind measurements to investigate the properties of several mountain wave events observed over Cerro Pachon.