Glacial erratic boulders of Snohomish County, Washington (Wikipedia) Glacial erratic boulders of Snohomish County are large glacial erratic boulders of rock which were moved to Snohomish County, Washington by glacial action during previous ice ages.
Referred to as the Lake Stevens Monster, the giant rock is considered the largest erratic in Washington and maybe in the United States. It measures 34 feet tall and 78 feet in length with a circumference of 210 feet.