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Glacial Erratics: Awesome Giant Rocks to Visit Around Seattle

Huge rocks carried by glaciers are fascinating and fun to climb on

Annie Fanning

Published on: October 21, 2021

Glacial Erratics: Awesome Giant Rocks to Visit Around Seattle

Martha Lake Airport Park Boulder
Martha Lake Airport Park glacial erratic

Martha Lake Airport Park Boulder, Lynnwood

Snohomish County Parks gets major props for preserving the erratic at Martha Lake Airport Park by cleaning it of graffiti and honoring it with an informational sign. Covered with spray paint, erratics can tell us very little. When we can see the stone and examine its natural color and texture, we can guess at its history.

About 18 feet tall, this lovely rock is probably greenschist, a mineral-rich basalt that has been chemically changed by heat and pressure long ago under the sea floor. This type of erratic is common in lowlands of the Puget Sound area.

Getting there: Drive to Martha Lake Airport Park at 200 146th St. W., Lynnwood, WA 98037. You’ll find the rock tucked behind the picnic shelter.

If you go: Bring your wheels! This park has a skateboard ramp and scooter-worthy paths. After your rock appreciation, chow on super nachos and quesadillas at Casa Guerrero (402 164th St. S.W., Lynnwood, WA 98087).

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