The Olympic Mountains were formed between 15 million and 55 million years ago when two crustal plates collided and drove the mountains up from the ocean floor. For eons, wind and rain washed sediments from the land into the ocean. Over time, these sediments were compressed into shale and sandstone. Meanwhile, vents and fissures opened under the water and lava flowed forth, creating huge underwater mountains and ranges called seamounts. The plate(s) that formed the ocean floor inched toward North America about 35 million years ago and most of the sea floor went beneath the continental land mass.

Mount Olympus, the highest mountain amongst the Olympic Mountains, is just under 8,000 feet--but they rise almost from the water's edge and intercept moisture-rich air masses that move in from the Pacific.  Ice Age glacial sheets from the north carved out the Strait of Juan Fuca and Puget Sound, isolating the Olympics from nearby landmasses. The Olympic Mountains were discovered by white men in 1774, when the roving Spanish sea captain Juan Perez sighted them as he sailed along the coast. He named them Cerro De La Santa Rosalia, but the name was not destined to last. Fourteen years later the British captain John Mears named the highest peak Mount Olympus.

These early explorers were content with only distant views of the mountains and it was not until 1854 that anyone was credited with climbing Mount Olympus. There was little reported exploration of this mountain wilderness until after 1880, and even today there are many places among the rugged peaks never visited by man.

Credits and Sources:

National Park Service. "Administrative History 1992." NPS.gov. http://www.nps.gov/parkhistory/online_books/olym/olym_adhi.pdf (accessed June 12, 2015).

National Park Service. "Geology Fieldnotes." NPS.gov. http://nature.nps.gov/geology/parks/olym/ (accessed June 15, 2015).

National Park Service. "Olympic: European and Euro-American History." NPS.gov http://www.nps.gov/olym/planyourvisit/upload/Euro-history_printer-friendly.pdf (accessed June 15, 2015).

National Park Service. Olympic Guidebook 1939. NPS.gov. http://www.nps.gov/parkhistory/online_books/brochures/1939/olym/sec1.htm (accessed June 15, 2015).