Erratic Rock State Natural Site 
Off OR 18, 6 mi- E of Sheridan, along Oldsville Ro
Sheridan, OR 97378
800-551-6949
http://www.oregonstateparks.org/park_135.php
State Park: Birding, Hike, Picnic, Walk, Water Sports
This 40-ton rock was deposited during a prehistoric flood. Other than this specimen, rocks of this type are only found in Canada. It was carried here on a iceberg during an Ice Age some 20,000 years ago, probably by way of the Columbia River. The rock was deposited when the ice melted. This is the largest glacial erratic found in the Willamette Valley. The trail to the rock provides an excellent view of Yamhill Valley Vineyards.