This resource monograph is one of a series designed as a teaching guide for field studies. Each guide centers around the exploration, observation, and interpretation of a field site in one of the four geological areas of Florida. Incorporated into the guides are many of the subject-matter schemes of the Earth Science Curriculum Program (ESCP) and three major process schemes: science as inquiry, comprehension of scale, and prediction. These guides also give the teacher information on the planning and execution of the field trip, as well as educational objectives, learning activities, and teaching materials available. The primary site for field study in this guide is the Devil's Millhopper, a collapse sink near Gainesville. Incorporated into the investigation of the area are activities in geology, history, mathematics, art, language arts, and environmental studies. The major theme for all these is change. Also included in this field trip is a stream study of Hogtown Creek. This guide contains directions for the activities, data sheets, and evaluation sheets. With some modification, these activities can be used at primary or secondary grade levels. (MA)