- 19,000 years ago marks the approximate time when glaciers crossed the present-day Canada–United States border into Western Washington, which is generally considered to be the beginning of the Vashon Glaciation.
- Deception Pass (gravelbeach.blogspot.com)
Much of Puget Sound is nothing but Pleistocene - with Vashon glacial deposits on the surface and older glacial and interglacial sediments peaking out from the lower portions of some of the bluffs. But at Rocky Point, on the west side of Whidbey Island, and in Skagit Bay, the Mesozoic re-emerges from the basement to form rocky islands and headlands.
- During the Vashon Glaciation, the Cordilleran Ice Sheet grew and advanced southwards at a rate of about 135 metres (443 ft) per year.
- Much of the current topography was formed through the erosion of the depression by the Cordilleran Ice Sheet during the Vashon Glaciation, which lasted from about 19,000 – 16,000 BP.
- The Vashon Glaciation is an extension of the Fraser Glaciation in which the Cordilleran Ice Sheet advanced south of the present day Canada–United States border into the Puget Sound region.
- The Vashon Glaciation lasted from about 19,000 – 16,000 BP (Before Present – present defined as January 1, 1950 for this scale).
- This southern part of the Cordilleran Ice Sheet is called the Puget Lobe.
- Vashon Glaciation (Wikipedia)
The Vashon Glaciation, Vashon Stadial or Vashon Stade is a local term for the most recent period of very cold climate in which during its peak, glaciers covered the entire Salish Sea as well as present day Seattle, Tacoma, Olympia and other surrounding areas in the western part of present-day Washington of the United States of America. This occurred during a cold period around the world known as the last glacial period. This was the most recent cold period of the Quaternary glaciation, the time period in which the arctic ice sheets have existed. The Quaternary Glaciation is part of the Late Cenozoic Ice Age, which began 33.9 million years ago and is ongoing. It is the time period in which the Antarctic ice cap has existed.
- Vashon glacier begins to melt and recede from Puget Sound region and Columbia Basin around 16,900 years ago (historylink.org)