The Olympic Mountains began life 35 million years ago as part of the ancient sea floor that thrust against the North American plate. Inexorable geologic forces fractured and folded these layers of rock and lifted them high into the air. Erosion and glaciers carved the valleys and peaks visible today. Rising directly out of the Pacific Ocean on the west, the mountains rise to their highest point, 7,969 foot tall Mount Olympus, 61 miles from this marker. The Olympics are bordered by the Pacific Ocean to the west, the Strait of Juan de Fuca to the north, and Hood Canal and Puget Sound to the east.
The range catches moisture-laden Pacific storms, causing about twelve feet of rain to fall each year on the west-facing valleys, sustaining the temperate rain forest. At higher elevations this precipitation falls as snow adding to glaciers that relentlessly carve the landscape. The east side of the mountains lie in a "rain shadow", with only 25 inches of annual rainfall and much dryer conditions.