The 0.4-mile Trail of the Whispering Pines winds its way through the forest near the visitor center. You get great views of pine trees, Lava Butte, and several nearby volcanoes. This path sits on part of Newberry Volcano, a 1,200-square mile shield volcano.
South Sister, pictured on the left above, is the youngest and most geologically active of the Three Sisters volcanoes. The mountain last erupted 2,000 years ago, but a “bulge” began forming in 1997. By 2001, the bulge grew to 9 inches in height and 10 miles in diameter. Its growth since that time has slowed considerably. Both South Sister and Newberry are regularly monitored for volcanic activity.