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Take-out Lid 3D Topographic Map Model



Topo salad tray model
Mastering the concept of contour lines using a 3-D topo salad tray model.

Title: Take-out Lid 3D Topographic Map Model

Topics: Topographic map, 3D model, geography, topography, elevation, contour lines

Length: 30-45 minutes


  • In this activity, students create a three-dimensional (3D) model of a topographic (topo) map by taping a paper map to one tray and drawing one contour line (a line of equal elevation) on each lid stacked above them map.
  • When stacked, the layers reveal a dynamic 3D visualization of a flat, two-dimensional (2D) map.
  • The example provided uses Angel Island in San Francisco Bay, California, but students can use any topo map.
  • Any tray shape can be used for this activity, but we have found that square, rectangular, or hexagonal lids are easier to work with than circular lids, which can easily rotate and become misaligned while drawing the lines.

Materials Needed:

  • Printed topographic map
  • Permanent marker
  • Clear, plastic lids, such as salad containers or take-out trays, minimum of five


  1. Select a feature you would like to model. Islands work well because they have well-defined boundaries, but anything with significant topographic relief works well, such as a hill, mountain, or canyon. If possible, choose a local feature that your students are familiar with.
  2. Download and print a map of your choice using the links at the bottom of this page. Alternatively, paper maps can also be purchased from the USGS Store.
  3. If necessary, adjust the size of the map so that the entire feature you are modeling is large enough to fit on one lid. To do this, crop the image to print at a different scale or enlarge/reduce the image on a photocopier.
  4. Cut the paper map to match the size of the lid. Then, trim a small amount of paper from the edges so that the map will fit snugly inside the lid.
  5. Use a marker to darken only the contour lines that you want to transfer to the lids. To decide which contour lines you want to transfer, remember two things: (1) The difference in elevation between adjacent pairs of contour lines is always the same. This difference is called the contour interval. The contour interval for the Angel Island Topo Model is 100 feet. (2) Only one contour line will be drawn on each lid, so choose contour lines that span the entire feature. Seven contour lines and seven lids were used to create the Angel Island Topo Model (pictured at the top of this page).
  6. Use clear tape to attach the map to the bottom of one lid so that you can see the map from above.
  7. Stack one empty lid on top of the first lid with the taped map.
  8. Using a permanent marker, trace one contour line on this lid. You will see that you drew one line of equal elevation that did not cross or intersect with another line. Tip: Oil from your hands may prevent the marker from writing clearly on the plastic. To avoid this, we recommend wiping each lid with a tissue before use and placing a tissue beneath your hand while tracing the lines to avoid smudging.  
  9. Stack another empty lid on the top of your model and trace another contour line on this lid.
  10. Continue steps #8 and #9 until you have traced all of the darkened contour lines.
  11. Label the name of the feature, a scale bar to show distance (feet, meters, miles, kilometers, etc.), and a north arrow.
  12. Congratulations, you made a 3D model of a topographic map! If you want to share your model, please tag us (@usgs_yes) on social media and use the hashtag #usgs3Dtopomodel. We would love to see your model and give you a virtual high five!

Find maps & background information below:

Download Free USGS Topo Maps

Download Free USGS Topo Maps

What is a topographic map?

What is a topographic map?

Angel Island Example

Angel Island Example