The purpose of this study was to examine middle school students' gestures during a geological field trip. Previous research on gestures has focused on understanding human development and exploring students' gestures can be helpful in improving understanding of students' communication in learning environments. In this study, middle school students from a gifted education center engaged in fieldwork along the Hantan-River to learn about and explain river formation processes. Using hermeneutics to interpret meaning from student gestures, researchers identified three types of frequently used gestures: deictic, imageable, and depictive, which served either a social communication purpose (explaining, asking, insisting, and giving evidence) or science communication purposes (visualization and temporal or spatial). Researchers offer implications about the role of gestures for helping novice learners communicate geoscience content and about the potential for gestures to be used by educators as an instructional resource for learners.