The Black Hills and other forests in the Rocky Mountains region have suffered epidemic mountain pine beetle attacks in recent years. Although the beetles are native to the Black Hills and commonly infest a few trees throughout the forest, drought conditions combined with a high density of trees led to an attack in the Black Elk Wilderness Area that spread into the Sylvan Lake, Cathedral Spires, Little Devil's Tower, and Needles Eye area, infecting nearly 3,000 acres in Custer State Park. In 2009-10, Custer State Park took a proactive approach by cutting and removing infested trees from this area. The main tree affected in the Black Hills is the ponderosa pine. The mountain pine beetle is a small insect about the size of a grain of rice that lives most of its life in the inner bark of pine trees. Tunneling by adult beetles, feeding larvae, and the introduction of a blue-stain fungus disrupt the movement of food from the needles to the roots, killing the tree. Efforts in Custer State Park to control the spread of mountain pine beetles have continued since 2005. The beetle population within the park grew from 2004-2009 and held steady in 2009-2010, and forest management techniques that discourage infestation appear to have stabilized population growth within the park while reducing pressure from the beetles and lowering future tree mortality.