Trees and Shrubs

Ponderosa pine and birch in fall colors overlooking the Niobrara.

NPS photo

Three major forest types converge in the Niobrara River valley: ponderosa pine, Eastern deciduous, and Northern boreal. Ponderosa pine forest is at its eastern limit in the river valley. The nearest designated forest area containing ponderosa pine is located in the Black Hills in South Dakota. Eastern deciduous forest has extended up the valley and includes bur oak, American elm, black walnut, green ash, basswood, and hackberry. Broadleaf shrubs and vines include sumac, western snowberry, gooseberry, wild plum, and wild grape. Northern boreal forest is found on cool, moist, north facing slopes and includes the Smith Falls aspen, Populus x smithii, a hybrid species of quaking and bigtooth aspen that is the only population of this species occurring in Nebraska. These plants apparently have survived as relics of the Pleistocene ice age, when they were more widely distributed on the Great Plains.