Keep them in a cool, quiet place until rangers or biologists are contacted. The forests of California are threatened with exotic species of insects, plants and diseases- pests for which California's native organisms have little defense. Discovered in 1995, Sudden Oak Death has done tremendous damage to State Park forests, killing hundreds of thousands of tanoak, coast live oak, Shreve's oak and black oak trees from Sonoma County to Big Sur. Recently, this same fungus has been found infecting the foliage of rhododendrons and native huckleberry. The trees infected with Sudden Oak Death are characterized by wilted, faded brown foliage.
Older leaves become pale green and within weeks turn brown.
On close inspection, some varieties exude dark brown sap on the lower trunks. These dead oak trees pose a severe fire risk, especially in dense forests. But more importantly they are a loss of a valuable and treasured California resource. Do not transport soil or firewood. Avoid driving or parking vehicles in areas where they may become contaminated with soil or mud.