What is Erosion? Erosion is the gradual degradation (breaking down) of rock and other natural material, by wind, water, gravity, and even animals. Erosion happens all around us on hillsides, the edges of riverbeds, beaches, and cliff walls. It is an entirely natural and necessary process; erosion is responsible for the dispersion and recycling of rocks and minerals into sediment, which enriches soil and provides opportunities for new life to emerge! However, human induced erosion is not natural, nor beneficial to our local environment. Scientists have estimated that global rates of erosion have increased 10-40 times its natural rate, due to human influence and activity. If you are looking for signs of human induced erosion, it is particularly obvious alongside walking trails in parks and forests. Every year, our Sierra Outdoor School Naturalists take hundreds of of students on field trips to Calaveras Big Trees State Park, aptly named