In "A Phenomenal Land Slide, Paper No. 984" in Volume 53 (1904) of the Transactions of the American Society of Civil Engineers, D.D. Clarke describes venturing "partly by rail and boat, but chiefly by stage or mudwagon, crossing the Coast Range, and occupying 36 hours or more," to spend three and half days measuring and sketching the slide. He'd been inspired to do so by a May 21, 1899 Sunday Oregonian article describing a slide that was 1/4 mile wide, four miles long, traveling two inches per hour, that "tears great trees and boulders from their places and hurls them into the bay."
Clarke estimated that 30 acres had slid 400 feet from May 10 to June 13, starting up at the 300 foot level, 1/2 mile in total length, and averaging 500' in width. Not quite as dramatic as the newspaper report, but still impressive. He reported that the ocean had already begun to scour away the end of the slide. Mike Neal says that what still juts out a bit in that location is very hard clay. Zoom in on the Google map and you'll see Neal's best estimate of the 1899 slide boundaries. It's very close to what's still sliding today. Coleman Creek, just north of the slide, was the source of Bayocean's water.
These landslides are just one way in which Cape Meares has been falling into the ocean for a millenia. Cliffs also crumble. Mike Watkins pointed out a cave out near the edge of Cape Meares that had collapsed since his childhood. Debris from similar collapses in the past formed Bayocean Spit and continues contributing to it today.

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