 According to the United States Census Bureau, Woodmohr has a total area of , of which is land and , or 0.15%, is water.The six mile square that would become most of Woodmohr was first surveyed in the summer of 1847 by a crew working for the U.S. government.In September 1849, another crew marked all the section corners of the six mile squares, walking through the woods and wading the swamps, measuring with chain and compass.