This year marks the 60th annual Cannon Beach Sandcastle Contest. In this 1960s photo, a crowd gathers on the beach for the event.

Cannon Beach’s annual sandcastle contest began with a tsunami.

After a March 1964 earthquake in Alaska caused a tidal wave to reach the Oregon Coast, residents of the town were left isolated when a bridge over Ecola Creek washed out, cutting off neighborhoods from one another.

In search of a pastime and hoping to boost summer tourism, residents took advantage of low tides to organize a day of sandcastle building on the beach. That grew into the Cannon Beach Sandcastle Contest, which is returning this weekend for a 60th year.

The Cannon Beach History Center and Museum’s “60 Years of Sandcastles” exhibit, on display through Friday, tells the story of the event through the eyes of longtime locals.

Three women — Margaret Atherton, her daughter Billie Grant, and Marion Crowell — organized the first contest, which saw just a handful of creations. By 1978, the event had grown to attract more than 1,200 contestants.

Annual posters, including many designed by Cannon Beach artist Bill Steidel, became part of the tradition.

In 2014, at its 50-year mark, the contest was designated an Oregon Heritage Tradition by the Oregon Parks and Recreation Department.

This year, the event starts on Friday with a demonstration from sand sculptor Bill Rose. Contestants arrive on the beach Saturday morning for the competition, which is still timed according to the low tide.