Marrowstone, Washington  Marrowstone is a census-designated place (CDP) in Jefferson County, Washington, United States. The population was 844 at the 2010 census. All Marrowstone addresses are in Nordland, Washington, and the ZIP code for Marrowstone Island is 98358. Marrowstone takes its name from Marrowstone Point, the northernmost point on Marrowstone Island. It was given the name "Marrow-Stone Point" in 1792 by the British explorer, George Vancouver, in describing the area's hard, clay-like soil. A post office called Nordland has been in operation since 1898. The community derives its name from Peter Nordby, the original owner of the town site. Marrowstone is located at (48.058323, -122.687943). According to the United States Census Bureau, the CDP has a total area of 6.3 square miles (16.4 km²), all of it land. Prominent land features include:  A narrow causeway connects the southwestern end of Marrowstone Island with the southern end of Indian Island. A short bridge joins the western side of Indian Island to the mainland of Jefferson County. Fort Flagler, a Washington state park, is situated on 784 acres (314 hectares) at the northern end of Marrowstone Island. It overlooks Port Townsend Bay and Admiralty Inlet, the entrance to Puget Sound. Fort Flagler was one of three forts, along with Fort Worden (near Port Townsend) and Fort Casey (on Whidbey Island), that guarded the entrance to Puget Sound. Mystery Bay State Park is another state park on Marrowstone Island, located on 10 acres (4 hectares) of Mystery Bay shorefront about a half-mile north of the Nordland General Store. It is primarily for boaters. Kinney Point State Park comprises at the south end of the island. Accessible only by boat, it is part of the Cascadia Marine Trail. Flagler Road (SR 116) runs along the western edge of Marrowstone Island, which is primarily low-lying. East Marrowstone Road runs along the eastern edge of the island, which consists largely of sandy bluffs, with the exception of the area near East Beach. The Nordland General Store is Marrowstone's only source of groceries. It is arguably the focal point of Marrowstone; on maps the town of Nordland (the address of all Marrowstone residents) is usually located at the site of the Nordland General Store.