Ahead of the lesson: print simple contour maps on half sheets of paper (see attached file). Each one is a little different e.g. some have steeper slopes; for capable students include river valleys (E1 and E2 on attached file). Make a duplicate copy of each contour map.
With students, look at a topographic map that shows the height of land in different colours, either on a real map, or projected e.g. this map of Hawaii: https://commons.wikimedia.org/wiki/File:Hawaii_Island_topographic_map-f…
Ask students how many mountains there are on the map (two or four), point out the colour changes as the height changes.
Then point out the lines between the colours - these are called contours and show where the land gets higher. The colours are not needed with these 'contour lines'.
Then look at a map that shows only the contours, lacking colour changes with height e.g. this map of North Vancouver and nearby Islands: http://www.canmaps.com/topomaps/nts50/toporama/images/092g06.gif
Show them the contours and tell students that they show how high the land is. Their spacing tells us how steep or gentle a slope is, and where there are river valleys and plateaus.
Tell students they will make their own model of a mountain from a simple contour map.
Demonstrate the activity, before students run it themselves (pairs work well):
Cut out a contour map around its outer edge, while the other student rolls out about half of the play dough to about 1cm thick, or until it is large enough to fit the contour map on it.
Lay the cut piece (showing the shape of the lowest level of the contour map) on the play dough and use the knife to cut out the shape. Lay the shape to one side of the mat.
Now, cut out around the next smallest contour line, and roll out a new piece of play dough (students can switch roles). Lay the (now smaller) contour map on the new rolled-out play dough and cut out the (new) shape. Lay the new play dough shape over the first one, using the duplicate contour map, to show where to lay the second layer over the first layer.
Repeat with the following contour lines, cutting out their shapes in play dough, and using the un-cut contour map to show how to align the layers on the growing mountain.
(For older students, more complex mountains with two peaks can be made.) If there is any doubt how to align one layer on the next, use a toothpick to help:
Before picking up the first paper contour cut-out, stick a toothpick through the paper and into the play dough in several places. When subsequent layers are made, push the toothpick through the same holes in the paper into the rolled-out play dough before removing the paper. The toothpick holes in the play dough can be aligned to place each layer in its proper position.
Once their mountains is made, students can cut their duplicate contour map along the outer contour line only, then bring their mountain and duplicate contour map to the tarp, where they are placed for display on separate halves of the tarp. As new mountains are added, place them next to the previous ones, and place the corresponding contour maps in equivalent positions in their own area. The growing landscape of model mountains will be reflected in the growing contour map assembly next to it.
(As students understand the relationship between the growing mountain landscape and the adjacent contour map, they can help direct where to place the contour maps correctly.)
As a class, look at the landscape and the contour maps. Refer back and forth while discussing and highlighting these features of a contour map:
The mountains look like islands in the ocean (the tarp is the ocean water).
Where are the steep slopes and the gentle slopes on the play dough mountains? Look at the contour maps to see what the lines do [lines are close together on steep slopes and far apart on gentle slopes].
Optional (and with warning to students that their creations will be modified): smooth out the sides of each mountain, so they look more like real mountains, commenting that the lines show the heights, but real mountains don't go up in steps.
Ask students to find valleys on the play dough mountains, which rivers might run down. Then show the same valleys on their contour maps - the contour lines have a distinctive shape, curving up and back, in a valley. Show them river valleys on a real map/the projected map (which likely also has a blue river line).
Refer back and forth between the landscapes while discussing and highlighting landforms that the students know about (e.g. mountains, hills, plateaus, valleys, deltas).
As a class, look back at a real contour map (preferably in an area that students are familiar with e.g. the same Cypress mountain map with the Sea-to Sky highway) and try to read the mountains: the steep slopes, the gentle slopes, the narrow river valleys (formed by water) and wide river valleys (formed by glaciers).
Optional and advanced: Students modify their mountains, then make a new contour map of their new mountain (not tested with a class).