In order to use the distribution of lake ice to analyze climate of a particular region, one must know which climatic factors are related to the freezing and thawing of lakes. The major goal of this study is to map the freezing and thawing of lakes in a particular region and to relate certain aspects of climate to these events. A second objective, which is actually a corollary to the primary objective, is to evaluate the effects of the morphology of lakes on their response to climate, and, after determining these effects, to examine the possibility of estimating mean depths of lakes remotely. The majority of investigations involving the interrelationship of lakes and climate have dealt with single lakes or, at most, lakes within a single region. To obtain a large scale regional picture of this interrelationship it was necessary to use aerial reconnaissance and remote sensing techniques. Since the detailed information that can be gathered when dealing with a single lake cannot be obtained in a regional study, the observations reported here must necessarily be more general in nature.