This study contributes to the literature by shedding light on students' learning by examining and comparing students' gestures in two educational contexts: geological field trips and classroom-based modeling activities. This study engaged 10 middle-school students in two different geological field trips and two classroom-based modeling activities and employed a hermeneutic approach to understand students' use of gestures in both settings. Using multimodal interaction analysis (MIA) students' gestures were explored to understand how students created and conveyed meaning using verbal and nonverbal interactions. The study found students' gestures conveyed scientific content and differing social roles in the two settings. The results suggest the frequency and type of gestures used in each setting may be complementary to students' development of accurate models. This study presents new classification criteria and characteristics to identify students' gestures. This study demonstrates gestures can be an important resource for learning when students are engaging in modeling activities.