In a number of places in the world are found trunks of trees thousands of years old, still preserved. In the Yellowstone Valley there are great stumps of petrified trees. Along the shores of the Chesapeake Bay not far from Baltimore are giant trunks of ancient Cypresses. These are found in an old peat bed covered with clay. In the uplands of the Little Missouri are many petrified trees which have ben washed out from the sand, stones, and shales. There is a small petrified forest in Europe, and at least one in the West Indies. Perhaps the most extended and best-known petrified forest is in Arizona along the Little Colorado River. This forest is near the towns of Adamanna and Holbrook. It is made up of 5 different areas, known as First Forest, Second Forest, Third Forest, Blue Forest, and North Sigillaria Forest. These forests are found in beds of a stone called marl, which covers the surface where the forests are. Many of the petrified trees are 5 feet in diameter and 50 feet in length. It is not difficult to understand what took place ages ago to change the trees into rock. All about there are evidences that there were once volcanoes and hot springs in this section. The forests were overrun by a flow of the hot alkaline water in which was a mineral called silica (sl´ -kå) . The wood cells of the trees were replaced by this silica, so that we now have mineral formations exactly in the shape of trees. Some of these petrified trees are like quartz; others are of beautiful agate, pearl, or jasper color. The most famous of the petrified trees is here shown. It is 100 feet long, and forms a natural bridge over a chasm 50 feet wide. Keystone ID: 13516 Note: All titles, descriptions, and location coordinates are from the original Keystone Slide documentation as supplied by the Keystone View Company. No text has been edited or changed.