Big Bear Valley, CA, April 12, 2014 – When the glaciers receded during the Pleistocene Age, they created unique open areas covered with miniature rare plants found only in Big Bear. These areas are known as pebble plains and have a soil composition of quartzite pebbles, deposited over eons, which prevent conifers from taking seed, thus preserving this ancient habitat for many millennia.
The Pebble Plain is home to seventeen protected plant species and four rare kinds of butterflies. Three of these butterflies are found nowhere else in the world. The plants are accustomed to the exact kind of soil found in the pebble plain. They receive just enough moisture and the right amount of sunlight they need to grow. Pebble plain habitats are open patches of rocks surrounded by Junipers, Pinions, and other pines. Plants and grasses grow low and sparse between the pebbles. There are pebble plains in the Baldwin Lake area, Gold Mountain, Holcomb Valley, Sugarloaf Ridge, and a series of ridge plateaus in Moonridge called the Sawmill Complex.
These areas are very fragile and the plants in this community grow very slowly, so when something disturbs the soil or pebbles, or crushes the plants, weeds that don’t belong there quickly move in. 150 acres of pebble plain were lost when Big Bear Lake was created. Gold mining, cattle grazing, rock collecting, off road vehicles, development, and fire suppression activities have all damaged pebble plain areas.
In 1990, the Forest Service and the Nature Conservancy developed a plan to protect this fragile habitat and the rare plants and butterflies associated with it. It is hoped that they will grow and thrive in the little pockets of pebble plain habitat that remain among the trees of the San Bernardino Mountains.