The Story of the ’Stack

PROMO Intro Haystack 512x219

Imagine, if you will, a portion of the northern Oregon coast 40 million years ago. Clatsop, Tillamook and Lincoln counties are at this point mere motes glinting across an abyss of geologic time, but the physical coordinates are more or less analogous. The climate is almost tropical, mammals and birds flourish in the absence of non-avian dinosaurs, and temperate deciduous forests have just become a thing. Newly forged by the inexorable roiling of plate tectonics, this hodgepodge landmass comprises ancient marine sediments thrust up from the deep, as well as remnants of volcanic archipelagoes rafted eastward and cemented onto the mainland. Here, the ridges and peaks of what will eventually become the northern Coast Range rise incrementally, nudged and folded up as the Juan de Fuca Plate is subducted by the North American Plate.

Fast-forward to sometime in the latter Miocene epoch (approximately 5-10 million years ago), as the North American Plate—and nascent northwest Oregon with it—drifts over a series of "hot spots" in the Earth's crust, where magma readily finds its way to the surface and, thus extruded, becomes lava which cools to rock. At a point almost one mile west of present-day Pacific City, an enormous blob of lava burbles up through a fissure in the overlying bedrock, solidifying into a vaguely conical—dare we say "haystack-shaped"?—dyke of intrusive basaltic rock. Intrusive, because it has erupted within a vast deposit of sedimentary rock, a comparatively soft substrate that shall prove far more yielding to erosional forces. The basaltic edifice, surrounded by sandstone and shale, is slowly disinterred by the wind and waves. After a few millennia, only a thin corridor of sandstone—known today as Cape Kiwanda—tethers the rock to the shore, and then even that is severed. The rest, as they say, is history.

So goes a prevailing theory regarding the rock's provenance. Today, looming 327 feet above sea level, Haystack Rock at Pacific City is the tallest of Oregon's coastal Haystack Rocks; the other two, found off Cannon Beach and Bandon's Devil's Kitchen Wayside, stand at 235 feet and 105 feet, respectively. As far as is known, these rocks are contemporaries (give or take several million years), born from similar volcanic origins. All are included within Oregon Islands National Wildlife Refuge, and all provide essential breeding and resting habitat for seabirds and marine mammals.