Can I grow olive trees in the Corvallis area? In the Eugene area?
Olive trees (Olea europea L. olive) are not recommended as a commercial crop in Oregon (see Oregon CropMAP Tree Fruits and Nuts). This is due to two reasons: olive trees are susceptible to cold temperatures (fruit damaged below 28F and trees damaged below 12F). The trees also do not do well in our wet soils during the winters. Keep in mind that these are recommendations for commercial/large acreage production. There are a handful of growers in the Willamette Valley, although local oil production is usually supplemented with olives purchased from California.
But on the other hand, you might find that your yard offers a microclimate that provides protected site with warmer temperatures and a well-drained soil. The Willamette Valley seems to be right on the edge of the preferred growing area for olives. It's always fun to experiment with new varieties of fruiting trees and shrubs, although that can get expensive if a cold winter kills your trees!