Thousands of years ago, cataclysmic floods inundated the Pacific Northwest and carried massive pieces of glaciers sailing across what is now Washington and Oregon. The floodwaters receded, stranding these icebergs. When they melted, they left behind large pieces of rock that had been carried from hundreds of miles away. Known as glacial erratics, these rocks differ in size and composition from native rocks.
The largest known glacial erratic in the Willamette Valley perches serenely atop a hill near McMinnville and weighs around 36-tons. The massive rock was transported from Canada. Visitors making the short hike to the boulder might be lucky enough to see the neighboring farm animals or native plants in bloom.
This location is a great place to enjoy a picnic lunch or simply take in the expansive views of the valley.
Know Before You Go
Though there are many signs for Erratic Rock in the area, it might be difficult to find at first because it is surrounded by private land. To get there, turn off Oregon Route 18 onto SW Oldsville Rd.
Park in the small pull-off on the side of the road and look for signs marking the trailhead. The park is open for day use only and has no facilities.