Airport Boulder, at
Martha Lake Airport Park in
Martha Lake, said to be "one of the largest glacial erratic boulders in urban King, Snohomish, and Pierce counties",[1] is approximately 20 feet (6.1 m) long on its longest axis and about twice a man's height. The erratic is composed of
greenstone,[2] and has long been used for
bouldering (rock climbing), with at least four ascent routes.[3][4]
Everett Boulder, erratic found 30 feet (9.1 m) underground at downtown construction site, Colby Avenue and Wall Street. 18 feet (5.5 m) long, and 10 feet (3.0 m) high, weighs approximately 300,000 pounds (140,000 kg).[6][7][8] The erratic briefly had over one hundred
Twitter followers and was eventually reburied.[9]
"Granite" is a 6-by-7-by-4.5-foot (1.8 m × 2.1 m × 1.4 m), 30,000-pound (14,000 kg) granite boulder discovered "under a bunch of
sticker bushes" during an October, 2015 construction project in Edmonds. After attempts to destroy the boulder resulted in destruction of the power equipment used, the city offered it for free to a city resident who would accept it on their property.[10][11]
Lake Stevens Monster near
Lake Stevens. 34 by 78 feet (10 m × 24 m) and 210 feet (64 m) in circumference. Largest known erratic in Washington State as of 2011[update],[12] and may be largest in the United States (but not North America; see the Alberta
Big Rock).
Unnamed erratics near Market Place road in Lake Stevens. Largest is unusual
pink granite, approximately 12 by 20 feet (3.7 m × 6.1 m) in size, and 10 feet (3.0 m) tall.[14]