To determine the habitat requirements for the three species of Michigan garter snakes which were found closely associated in the same area was the object of the following study. Realizing the difficulties involved in a problem of this sort, the author planned to approach it through field observation rather than by experimentation. By intensive study of a population including all three species, recording over a period of three years all data that appeared pertinent, it was hoped that clues would be uncovered leading to a better understanding of the ecological association of the species concerned.