Learning geoscience and becoming a professional geoscientist require high-level spatial thinking. Thus, geoscience offers an intriguing context for studying people's mental representations and processes as they pertain to large-scale, three-dimensional spatial cognition and learning, from both cognitive science and geoscience perspectives. This paper discusses major tasks that professional geoscientists and geoscience learners deal with, focusing on the spatial nature of the tasks and underlying cognitive processes. The specific tasks include recognizing, describing, and classifying the shape of an object; describing the position and orientation of objects; making and using maps; envisioning processes in three dimensions; and using spatial-thinking strategies to think about nonspatial phenomena. Findings and implications from cognitive science literature that could be incorporated into geoscience teaching and some questions for future research are also discussed.