Washington’s largest erratic ‘discovered’ in Lake Stevens ?

By Dave Tucker

The back side of the Lake Stevens erratic towers out of the woods. Bob Mooers photo. Click to enlarge

What must be among the largest glacial erratics in the US has been spotted in Lake Stevens. This hulking brute rivals if it does not surpass Waterman erratic (Whidbey Island), the reigning ‘Mother of All Erratics’ in the Northwest. The Lake Stevens erratic was brought to my attention by two Lake Stevens policemen, Craig Valvick and Matt McCourt. They have carefully taken an initial set of dimensions: it is 34 feet (10.36 m) tall and 78 feet (23.77 m) in length. The circumference is 210 feet (64 m). by contrast, the estimated dimensions of the Waterman erratic, as reported on this website, are 33 feet (10 m) high, and measures 60 feet on each side (18 m).

An expedition was made to examine the rock. I went down from Bellingham with Bob Mooers, and we met Craig and Matt there, as well as Donn Charnley, Barbara Magnuson, and Corinne Waters, all erratic fans from the Edmonds and Shoreline area. We determined that the rock is composed of greenstone, in places serpentinized. Greenstone is a low-grade, metamorphosed sea floor basalt. Another page on this website describes the rock in more detail, and compares it with the previous champion.

Getting there: The Lake Stevens erratic is in a tiny park, maintained by the people of the neighborhood. From I-5 in Everett, head east on US 2 for 2 miles. Take the 20th Street exit straight ahead (east) and go about a mile to  the stoplight at 83rd Ave, turn left (north) and take it almost to the cul de sac at the end, 1.3 mile north of 20th. The erratic is in the little park on the right before the end of the street. There is an informal trail around to the dark, looming east face, rising vertically for 34 feet.  47° 59.816’N 122° 6.954’ W  NAD 83

There are rock fragments lying on the ground on the east side, if you wish to examine a fresh rock surface. Please, NO HAMMERS!

Read more about erratics in general on this website, and find out where some other big ones lurk.

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8 Responses

  1. I sure look forward to finding out where this huge hunk of greenstone came from!

    • Kitty,
      There are a couple of suspected sources. Right now we are trying to figure out how to obtain a volume for this big hunk o’ gren rock. We can calculate density. V x D = mass!
      DT

  2. Surprised noone noticed before now. The development around the rock was put in well over 15 years ago

    • I’m not surprised, actually, it is well hidden away. The rock can’t be seen from anywhere except the cul de sac in front. Someone would have to recognize this monster for what it is, rather than thinking ‘oh, that’s just a rock outcrop’. If no one in the neighborhood was geologically inclined, I’d think obscurity was almost guaranteed. Everyone who likes erratics owes a big ‘thank you’ to eagle eye officers Craig Valvick and Matt McCourt..

  3. Is this rock on private property?

  4. […] (very difficult) hole, excavate a free rock. While I sadly do not have one of the semi-truck-sized erratics like my neighbors do down the street, I’ve got pebbles, cobbles, and boulders from about a […]

  5. I took Geology 101 at Shoreline CC in 1976 from Donn Charnley. It was fascinating to come across his name after so many years. Greetings and best wishes to him and many thanks for the wonderful class he taught.

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