 It is bordered on the west and north by the Northern Oregon Coast Range, on the south by the Chehalem Mountains, and on the north and east by the Tualatin Mountains (or West Hills).The county's major roads include small sections of Interstate 5 and Interstate 205, the Sunset Highway, Oregon Route 217, Oregon Route 47, Oregon Route 10, Oregon Route 6, and Oregon Route 8.Public transportation is primarily operated by TriMet and includes buses, the Westside Express Service commuter rail, and MAX Light Rail.