Using carbon paper, I traced the contours onto fiberboard. I then cut out the fiberboard along the contour lines and glued them together, building things up like a layer cake.
I then filled in the contours with flexible modeling paste to give a more gradual look. Then the final boards were glued onto a bottom sheet of plywood for stability, and edged with thin plywood for support. The last step was spray-painting the entire board an earthy brown.
Transferring the Map Data to the Boards
Using carbon paper, I traced all the map detail onto the boards.