An early resource extraction in Washington State was limestone. Limestone deposits were mined on Orcas Island and San Juan Island. The mines and associated kilns on San Juan Island are a bit better known as State Park, Lime Kiln State Park is located at the site. Kilns and small mines were also located at the upper end of East Sound southwest of what is now the Town of Eastsound (the town name runs the two words together). I came across one of the old kilns covered with English ivy.
I know of at least two other kiln sites on Orcas. Another kiln site is located on San Juan Land Bank property at Judd Cove (sjclandbank.org/judd-cove-preserve-orcas-island) and is open to public access.
USGS topographic map indicating two kiln sites
The kiln shown above is not on the map
The limestone is in or were in three different formations: the Eastsound Group, the Deadman Bay Volcanics and the Orcas Chert. In all three cases the deposits are small in extent. However, the high carbonate content, access to water transport and abundant fuel (forests) for firing the kilns allowed for these small deposits to be profitable. There are scattered old quarry sites at many sites near the water on the island. The mining took place as early as the 1860s and was still in operation into the 1910s.