Resistivity gages were installed at various locations of the test section. They consist of circular rings mounted on vertical rods. The resistance between each set of rings is determined on a periodic basis. In general the presence of liquid water results in low resistance values. In the wintertime, the presence of frozen materials will result in higher resistance values. The presence of moisture exhaxerbates variations in resistance values between seasons. In this project, resistivity gages are used to estimate the depth of frost in the wintertime as well as the depths of the thaw lines in the spring. Below is a plan view of the instrumented section of DIA's Runway 34R/16L. The locations of the Resistivity gages are highlighted.