Assign each student a different continent or country to make a map of. They will mix 1 cup of salt, 2 cups of flour and 2 tsp. of cream of tartar. Then they will slowly add in the water, and knead the dough until it is smooth and soft. They can smooth out the dough for oceans and rivers, or contour the dough for mountains and hills. When the dough is dry, they can paint it.
Have each student pick a favorite explorer. First, they should make a salt map of the area the explorer visited. After the salt map dries, have them paint lines showing the exact routes the explorer took. They can display their maps in a two-sided box. One side will have the map and the other side biographical information and a picture of the explorer.
Instead of asking the students to make a map of some historical place or major country, ask them to make a map of an area that they frequent every day. Ideas include making a map of the route that the students follow on their way to school, a map of their own home or a map that shows the school and schoolyard.
Tie the salt map into other subject areas, aside from geography, so that students can see their varied purposes. For example, you could allow the students to draw a story map on the dough, using contoured surfaces to indicate rising or falling action. The students could read a story, and then use small figurines, tiny boxes or items sculpted out of the dough to represent the words from the story.