[3][4] The Washington State Department of Transportation (WSDOT) found in 2007 that, on average, more than 2,800 motorists utilize the road daily south of the northern terminus in Cathlamet, making the highway the second busiest state route in the county, after SR 4 at Boege Road, which more than 4,100 motorists utilize daily.

From the dock, the road travels north past the island's interior, before turning northwest to parallel the Cathlamet Channel.

After intersecting Little Island Road, the highway immediately turns onto the Julia Butler Hansen Bridge spanning over the Cathlamet Channel.

[11] In 1939, the year the Julia Butler Hansen Bridge opened,[14] ferry service ceased on the Puget Island – Cathlamet run.

[11] The Julia Butler Hansen Bridge, which currently carries the route of SR 409, which will be designated in 1964,[15][16] from Puget Island to Cathlamet, opened in August 1939.

President Franklin D. Roosevelt commenced the five-day celebration of the bridge's opening with a ribbon cutting, remotely controlled from the White House via telegraph.