Black Locust (Robinia pseudoacacia) is a common presence on both sides of the Cascades. This Appalachian native was brought over in the 1800s to the region, and it's grown here ever since. There seems to be some controversy about black locust. Some claim it is invasive, while many others view it as a naturalized species.
Black locust can be found on both sides of the Cascades in a wide range of climates.
Black locust are easy to identify and hard to mistake. They have distinctively furrowed bark and quite large thorns. Do not walk around them barefoot! You might find yourself with a thorn in your foot, as I once witnessed happen to a classmate.