"I hate to blow the whistle on the Black Hills, but the hills literally look black," a colleague who recently drove through the area told me.

Western South Dakota, particularly the 1.5-million-acre Black Hills National Forest, is suffering from an epidemic of mountain pine beetles. The bugs are taking an enormous toll on the ponderosa pines that have been a part of the scene in the popular tourist area for decades. The beetles bore under a tree's bark, eventually robbing the needles of nutrients. The result is darkened trees that stand like toothpicks against the hills.

Not exactly what visitors expect.

Even if road-tripping travelers might find views of dead trees unsavory, beetles have always been an integral part of forest health in the area, according to Frank Carroll, a forestry expert in Custer, S.D. Beetles and that other dreaded scourge, fire, used to work together to keep the forest in balance, killing off some trees and opening up the forest floor for new seedlings. According to Carroll, "Nature is hitting the reset button on the Black Hills."

When Custer's Black Hills Expedition of 1874 encountered the region, just 30 to 70 trees grew on an acre of land. More recently, fire-suppression efforts fostered a thick growth of green trees — until the beetles starting munching their way up the hillsides. The critters thrive in dense stands.

With an eye to tourism, work continues on saving the most cherished vistas in the Black Hills, including Mount Rushmore and Custer State Park. There, and on hundreds of vulnerable acres beyond, trees are treated with insecticide and forests are thinned by downing trees. So at the most iconic of spots, expect to find plenty of shade — and possibly a view less impeded by tall trees.

Send questions to travel editor Kerri Westenberg at travel@startribune.com. Follow her on twitter @kerriwestenberg.