 SSH 1S was created in 1937 during the formation of the primary and secondary state highways , traveling on a 57 @.@ 60 @-@ mile @-@ long ( 92 @.@ 70 km ) route east from Primary State Highway 1 ( PSH 1 ) and U.S. Route 99 ( US 99 ) north of Mount Vista to intersect SSH 1U in Battle Ground and turned north towards Amboy and west to end at PSH 1 and US 99 in Woodland . After PSH 1 and US 99 was realigned onto a four @-@ lane limited @-@ access highway in the late 1940s , SSH 1S was extended south over the old highway to intersect PSH 1 and US 99 . 
