https://github.com/davepinch/pinchy.cc/blob/master/content/sites/historylink.org/File/5087.snippet-west-of-the-cascades-1-3.md
Ice Age Boulders in Drayton Harbor (washingtonlandscape.blogspot.com) Drayton Harbor is a shallow bay just south of the Canadian border. The City of Blaine is located on its northeast and southwest sides such that the small city has two parts separated by the bay.
Vashon glacier begins to melt and recede from Puget Sound region and Columbia Basin around 16,900 years ago (historylink.org)