OR 10 separates from OR 99W a few miles south of downtown, and proceeds along Capitol Highway through the Portland neighborhood of Hillsdale.

Along here, it is a surface street, which cuts through the southern part of Portland's West Hills.

West of that interchange, the street name changes to Farmington Road, the eastern part of which is not a state highway, and comes a block parallel with Oregon Route 8 in front of Beaverton High School.

OR 8 and 10 do not intersect, but it is not uncommon for commuters to use the frontage road for the OR 217 interchange or another surface street to change between the routes.

Milepoints are as reported by ODOT and do not necessarily reflect current mileage.