RCW 47.17.040
RCW 47.17.040: State route No. 9.
A state highway to be known as state route number 9 is established as follows: Beginning at a junction with state route number 522 north of Woodinville, thence northerly by way of Snohomish, Arlington and Sedro Woolley to a junction with state route number 542, in the vicinity of Deming; also Beginning at a junction with state route number 542, in the vicinity of Lawrence, thence northerly to the international boundary at Sumas.