Wash. Rev. Code § 47.17.735
A state highway to be known as state route number 525 is established as follows: Beginning at a junction with state route number 5 in the vicinity south of Everett, thence northwesterly to the state ferry terminal at Mukilteo; also From the junction with state route number 526 at Mukilteo, thence southerly to a junction with state route number 525; also From the state ferry terminal at Mukilteo via the state ferry system northerly to the state ferry terminal at Clinton; also From the state ferry terminal at Clinton, thence northwesterly to a junction with state route number 20 in the vicinity east of Keystone.
[ 2001 c 130 s 1; 1994 c 209 s 8; 1973 1st ex.s. c 151 s 15; 1970 ex.s. c 51 s 148.]