Characterizing spatial thinking and the development of spatial expertise is essential to understanding how to train geoscientists to succeed in both academia and industry. The Spatial Intelligence and Learning Center has supported an eight-year-long collaborative research program, which brings together disciplinary expertise in cognitive science and geology to characterize and develop spatial thinking in the geological sciences. To facilitate our understanding of science education and practice, we have characterized the spatial skills of geoscience discipline experts and the spatial thinking impediments experienced by students studying the geological sciences. In this chapter we review recent research on measuring and improving spatial thinking skills in the geosciences and on characterizing individual differences in spatial thinking, including the role of gender and age. We conclude with a discussion of important unanswered questions and some directions for future research. The research discussed here may help guide the development of best practices for spatial thinking training in both academic and industry settings.