The two-lane highway travels east from SR 19 in Port Hadlock-Irondale across the Portage Canal to Indian Island and Marrowstone Island, turning north and ending at the entrance to Fort Flagler State Park.

The highway travels east as Nees' Corner Road over Chimacum Creek and through the community of Port Hadlock before crossing the Portage Canal onto Indian Island.

SR 116 continues east on Indian Island as Flagler Road along the coast of Oak Bay and turns north along Scow Bay onto Marrowstone Island, entering a wooded area.

The highway continues north through central Marrowstone Island and passes through Mystery Bay State Park before ending at the entrance to Fort Flagler State Park.

In 2011, WSDOT calculated that the busiest section of the highway was its western terminus at SR 19, carrying 6,500 vehicles, while the least busiest section was the eastern terminus at Fort Flagler State Park, carrying 440 vehicles.