Spatial thinking is a cognitive skill that can be used in everyday life, the workplace, and science to structure problems, find answers, and express solutions using the properties of space. It can be learned and taught formally to students using appropriately designed tools, technologies, and curricula. This report explains the nature and functions of spatial thinking and shows how spatial thinking can be supported across the K-12 curriculum through the development of appropriate support systems. A geographic information system (GIS) is an example of a support system that, with recommended redesigns, can foster spatial thinking across the curriculum. The report calls for a national initiative to integrate spatial thinking into existing standards-based instruction across the school curriculum such as in mathematics, history, and science classes; it does not require the development of a new, separate course focusing solely on spatial thinking. The goal of this initiative is to create a generation of students who learn to think spatially in an informed way.