In 1942 the Forest Service established the Lava Cast Forest Geologic Area, approximately 5 square-miles of landscape that is completely dominated by a 6,000 year-old basalt lava flow, the remains of the forest that once was, and vegetation that tirelessly struggles to rebuild a forest once again.
Although the difficult access includes 9 miles on a bumpy gravel road, this paved interpretive loop justifies the journey with unusually educational insights into the powerful impact of volcanic activity. This lava flow burned though and decimated an ancient forest as it oozed downhill from a fissure on Newberry Volcano's northwest slope. That forest was once dominated by massive old-growth ponderosa pines, a species that is heavily reliant upon and well adapted to forest fire. Some individual specimens were so large that the lava flow wasn't able to knock them down. Instead, the flow would surround the tree, and as the tree burned with resistance, the lava would solidify around it, creating a Lava Cast Forest.
The forest is still composed of ponderosa pines, but the rugged landscape is also host to the occasional white fir, lodgepole pine, ground juniper, gray rabbitbrush, and magenta Cusick's monkeyflower. Enjoy this walk, and keep your eyes peeled for relics in this living exhibit.