The Hall of North American Forests explores the ecology and variety of the forests of North America—from a northern spruce and fir forest of Ontario to a giant cactus forest in Arizona—in addition to highlighting the forest food web and presenting techniques for protecting forests.

The hall’s dioramas showcase typical wildlife in a range of locations—including a mixed deciduous forest in the Great Smoky Mountains, piñon and juniper forests of Colorado, and a coastal plain forest in South Carolina—with trees, flowers, birds, mammals, and insects specific to each habitat. The Forest Floor diorama depicts a cross-section of soil, enlarged to 24 times actual size, to illustrate the process by which natural debris is broken down into nutrients.

The hall also features a slice of a 1,400-year-old sequoia tree, underscoring the immense size and longevity of this species, as well as a display that illustrates how environmental stresses such as defoliation, windstorms, and fire can affect tree growth.