The Oregon White Oak can be identified by its smooth green leaves with 5 to 9 rounded lobes and acorns with a bowl-shaped cap. They can grow to be 120 feet tall and 10 feet in circumference and live up to 500 years.
Oregon White Oaks savannas were once widespread in the Willamette Valley. Native Kalapuyans maintained these savannas through purposeful field burning. They would bury the acorns produced by the oaks in hemlock bough lined pits and baskets in the mud below flowing springs to leach out the acorn’s tannins. More than 100 soaking pits were found at a several hundred year old site on Sauvie Island. It is estimated 25,000 acorns per pit were processed for a total of 2.5 million acorns per year during bumper crop years. Now, more than 99 percent of oak savannas in Oregon have been converted to urban areas, farms, and other developments. Metro and the Confederate Tribes of Grand Ronde are performing prescribed burns of the Quamash Prairie Natural Area west of Tigard to maintain the oak savanna there.
