 the tualatin valley is a farming and suburban region southwest of portland, oregon in the united states. the valley is formed by the meandering tualatin river, a tributary of the willamette river at the northwest corner of the willamette valley, east of the northern oregon coast range. most of the valley is located within washington county, separated from portland by the tualatin mountains. communities in the tualatin valley include banks, forest grove, cornelius, hillsboro, aloha, beaverton, sherwood, tigard, and tualatin. == history == in the early 19th century, the valley was inhabited by the atfalati, a hunter-gatherer kalapuyan band of that spoke a dialect of northern kalapuyan. in the mid
Landforms_of_Washington_County,_Oregon Regions_of_Oregon River_valleys_of_the_United_States Valleys_of_Oregon