The 75th Round Rock Contest entry window opens! Drop off rocks at the front desk anytime July 21-31, 2026. Make sure to complete your entry form and test your rock to ensure it qualifies for size. In general, entries must be no smaller than a ping pong ball and no larger than a softball. All entries must have been found in Washington State. The traditional cash prizes still prevail!
The Basics
The rock must have been found in Washington State.
It must not have been manipulated by humans in any way (nature is okay).
The basic size limits are generally equivalent to a ping pong ball on the small side and a softball on the large side.
Rocks are judged for “sphericality,” as in round like a ball not like a skipping stone.
All rocks must be accompanied by an entry form.
Top five rocks become part of the Harbor History Museum collection, but other rocks may be picked up after the results of the contest are announced. We display all round rock entries at the museum for about a month after the winners are announced.