Olympic rocks tell of their having been formed of mud, sand, and lava, uplifted from the sea; they tell of earth disturbance that alternately submerged the land beneath the sea and elevated it into mountains. The rocks and the shape of the land also tell of colder climates, when ice from the north made almost a glacier island of the Olympic Mountains, and of mountain valley glaciers which sculptured the mountains during thousands of years. The rugged beauty of the Olympic high country, enhanced by scores of mountain lakes, bears testimony to the former presence of these extensive glaciers. Only about 11,000 years have passed since the last wave of northern ice retreated and laid bare Olympic rocks. Since then the moist and gentle climate has favored the growth of plants and the development of soil. The present Olympic forests and flowering meadows are products of a succession of plantlife from the first lichens and mosses that grew on Olympic rocks. Animals returned when the ice retreated. Plant eaters and meat eaters, large and small, throve in abundance. When primitive man came, he found the land and sea kindly. He easily obtained what he needed for food, clothing, and shelter without depleting the supply. While most of the Northwest was being explored and settled by the white man during the 19th century, the bulk of the Olympic Peninsula remained virtually unknown. Its rugged mountains, dense forests, and isolation contributed to the delayed advance of modern civilization to this northwesternmost corner of conterminous United States. The Olympic Peninsula thus remained one of the last frontiers, and the park retains genuine wilderness quality, even to its boundaries which descend to sea level. In this piece of original America the perceptive eye and mind will find a functioning model of nature—a model of earth forces, climate, and life. The Mountains Are Formed The present Olympic Mountains were born between 12 and 20 million years ago when western Washington was pushed up into a great range that extended from Cape Flattery southeastward to the eastern part of the State. At the same time, the land to the north and south was depressed and remains depressed today as Juan de Fuca Strait and Chehalis Valley, respectively. The Olympics were further elevated about 5 million years ago. This coincided with the building of the Cascade Mountains and the down-folding of the land between to form the Puget Sound trough. The Olympics were now isolated, having lowland on all sides. Olympic rocks formed in shallow seas that at least five times have covered western Washington. Sediments washed from adjacent land areas and accumulated on the sea bottom. Muds became shales and sands were cemented into sandstones. Molten lava erupted through these beds and was quickly cooled by the water. Thousands of feet of rock material formed in this way. [Illustration: Moss-covered tree]