Depends on where you're at in Washington. If you're in eastern Wa. near Yakima (or thereabouts) you'd use what the Yakamas preferred, Garry Oak which covers the hillsides all along the eastern slopes of the Cascades foothills. If you're farther north central, use Ocean Spray (ironwood to the Salish and Spokanes) or Mock Orange. Along the coast, yew, vine maple and ocean spray were used. Black Locust was brought with the white settlers and I'm pretty sure was not a native wood to Washington but we have tons of it everywhere now.