Sine is an unincorporated community in Grays Harbor County, in the U.S. state of Washington. [1]
A post office called Sine was established in 1905, and remained in operation until 1910. [2] The community has the name of Jackson Sine, an early settler. [3]
47°01′53″N 123°15′53″W / 47.03139°N 123.26472°W