During the misty mid-June day I took this photograph in Case Inlet, an eastern bay of the Southern Salish Sea, the tidal swing was nearly 14 feet. A swing of 18 feet is not uncommon . In the photo the tide begins its rise from a minus low.
A different kind of sea level rise will mark this shore in a profound way in coming decades. As a “mid-range” projection a permanent rise of two feet is predicted by the end of this century . Eventually the boulder’s twenty circles will disappear by barnacle, erosion, and/or inundation. Does it matter? Many lives and species will have been dramatically decimated by that time given current trends. How does this pending catastrophe matter? 
Meanwhile these circles story forth. Messages of cycles we moderns are unlikely to decipher, or indeed heed, except in general speculative terms . To my knowledge this is the only petroglyph in the Puget Sound area that is entirely circles with no apparent iconic referencing . Listen for a moment in this time of change
 By comparison the tidal swing that day in Florence, Oregon, was 7 feet
 Not counting the increasing flood risks. See: http://www.climatecentral.org/ Also: http://www.climatecentral.org/pdfs/SLR-WA-PressRelease.pdf
 The Anthropocene project: virtue in the age of climate change by Byron Williston (2015 Oxford University Press ) is a sharply provocative and convincing examination of the approaching catastrophe. He explores the ethics and morals of choice and denial. https://byronwilliston.com/
 There appears an absence of formal documentation of this and a nearby petroglyph boulder, though a flickering of images appear on the internet without details. Its age or purpose is unknown. Some speculate that this type of imagery in sea-edge or riverine zones is related to abundance, as supplication or as gratitude. Little proof of intent exists.
 Though many of the few Puget Sound petroglyphs are composed of circular elements, often suggesting eyes and faces. There are two locations I’ve visited on the Oregon coast with carved circles on sea-edge boulders: An Oregon coast boulder
Circles Boulder in Salish Sea