Wash. Rev. Code § 47.17.445
A state highway to be known as state route number 231 is established as follows: Beginning at a junction with state route number 23 in the vicinity northwest of Sprague, thence northerly by way of Edwall to a junction with state route number 2 in the vicinity west of Reardan; also Beginning at a junction with state route number 2 in the vicinity of Reardan, thence northerly by way of Long Lake across the Spokane river, thence northeasterly by way of Springdale to a junction with state route number 395 in the vicinity of Chewelah.
[ 1970 ex.s. c 51 s 90.]