I use this as a cumulative project with my third graders to assess their learning and understanding of regions of the United States. I use the McGraw-Hill curriculum in 3rd grade, but this could be used with any social studies curriculum and is easily adapted to higher or lower grades.
After studying the five regions of the US with your social studies curriculum, students create a postcard to demonstrate their understanding of what makes a region unique. They create a postcard image showing either a well known landmark or specific vegetation from their region. Then, they create their ‘letter’ on the other side. Students specifically mention the region, and three references to either landmarks, cities, states, vegetation, climate, or natural resources unique to the region.