[5] The highway crosses over Blackjack Creek and turns south onto Bethel Avenue, passing between Sunset Lane Cemetery and South Kitsap Discovery Alternative High School before a roundabout, where SR 166 turns east onto Mile Hill Drive.

[6] The highway ends as Mile Hill Drive at an intersection with Whittier Avenue near the eastern city limits of Port Orchard.

In 2011, WSDOT calculated that between 14,000 and 18,000 vehicles per day used the highway on the Kitsap Peninsula, mostly in Downtown Port Orchard.

[2] The highway between SR 16 and Port Orchard is located north of unstable slopes that cause mudslides after heavy rainfall.

[16][17][18] SR 166 was extended 0.15 miles (0.24 km) east on Mile Hill Drive in Port Orchard from Payseno Lane to Whittier Avenue in 2010,[1][19][20] because Kitsap County refused to maintain the road within Port Orchard city limits.