The California red-legged frog, threatened for decades by spreading subdivisions, pesticides and logging, has found a sanctuary in the Sierra Nevada. The U.S. Fish and Wildlife has approved an agreement between two conservation organizations permanently protecting a 48-acre site known as the Big Gun Preserve near Foresthill in Placer County. The wildlife service listed the frogs as threatened in 1966 under the Endangered Species Act. The land is owned by a unique nonprofit company called Westervelt Ecological Services, the conservation arm of a century-old Alabama lumber company, which buys up properties to preserve wildlife habitats and endangered natural environments. The...