Jarrell Cove State Park

McMicken Island Marine State Park is a public recreation area on Harstine Island in south Puget Sound, Mason County, Washington. The state park's 222 acres (90 ha) include 11.5 acres (4.7 ha) of forested McMicken Island and 1,661 feet (506 m) of saltwater shoreline with a sheltered cove. A sand bar connects McMicken Island to Harstine Island at low tide. Park activities include hiking, boating, and harvesting shellfish. The park is administered as a satellite of Jarrell Cove State Park. It bears the name of William C. McMicken, who was Washington Surveyor General from 1873 to 1886.

The Harstine Island ferry connected Harstine Island with mainland Mason County, Washington across Pickering Passage in south Puget Sound until 1969 when the ferry was replaced by a bridge.

Herron Island is an island in central Case Inlet in the southern part of Puget Sound in the U.S. state of Washington. The Pierce County island has a land area of 1.2326 km² (304.57 acres) and a population of 151 persons as of the 2010 census. Herron Island is one of the few privately owned islands in Puget Sound. All access to the island is by boat, mostly aboard the HMC ferry, the "Charlie Wells", and a guest pass signed by an HMC member is necessary to board the ferry. The island is 1.25 miles (2.01 km) long, and 1/2 mile (800 m) across. Corporate properties include the North Beach Park and small boat docks, the South Beach (undeveloped), roads and rights of way, Goodpastor Park and adjacent wetlands, Community Building and Fire Station, water system, ferry and ferry docks, as well as numerous greenbelt lots throughout the island. All other land is privately owned. Ownership of waterfront lots includes the tidelands down to the mean sea level.

Pickering Passage is a strait, in the southern end of part of Puget Sound in the U.S. state of Washington. Entirely within Mason County, the Pickering Passage separates Hartstine Island from the mainland, and connects Totten Inlet with the north end of Case Inlet. Pickering Passage flows past the mouths of Hammersley Inlet, Totten Inlet, and Eld Inlet. It is a nutrient rich area, producing oysters that grow very quickly.

Case Inlet, in southern Puget Sound in the U.S. state of Washington, is an arm of water between Key Peninsula to the east and Harstine Island to the west. Its northern end, called North Bay, reaches nearly to Hood Canal, creating the defining isthmus of Kitsap Peninsula. Case Inlet is the boundary between Pierce County and Mason County. The southern end of Case Inlet connects to Nisqually Reach, part of the southern basin of Puget Sound. Herron Island lies in Case Inlet. Case Inlet was named by Charles Wilkes of the Wilkes Expedition of 1838–1842, to honor Augustus L. Case, one of the expedition's officers. From the 1870s to the 1920s, transportation needs of the communities along Case Inlet were served by a small flotilla of steamboats.

Grapeview is a census-designated place (CDP) in Mason County, Washington, United States. The population was 954 at the 2010 census. It was part of the former Allyn-Grapeview CDP that was broken up into Allyn and Grapeview in 2010. Grapeview is connected to State Route 3 via Grapeview Loop Road. Grapeview is home to a small Puget Sound Maritime Museum, and the Fair Harbor Marina.

Stretch Island is an island in Case Inlet in the southern part of Puget Sound in the U.S. state of Washington. It forms part of the unincorporated Mason County community of Allyn-Grapeview. The island has a land area of 1.2179 km2 (300.95 acres) and a population of 162 persons as of the 2010 census. On the island's north side, it has buoys for overnight mooring, and Stretch Point State Park, a small state park only accessible by boat. Stretch Island was named by the Wilkes Expedition in 1841 for crew member Samuel Stretch. From the 1870s to the 1920s, transportation needs for Stretch Island and other communities along Case Inlet were once served by a small flotilla of steamboats. The local community based monthly newspaper called the North Bay Review, services Allyn.

Stretch Point State Park is a public recreation area occupying eight acres (3.2 ha) of land on the northern tip of Stretch Island in Mason County, Washington. The state park is only accessible by boat and is administered as a satellite of Jarrell Cove State Park.

Reach Island, or Treasure Island, is an island in Case Inlet in the southern part of Puget Sound in the state of Washington, United States. The island's original name was Oak Island, but was later renamed it Reach Island due to its southern neighbor Stretch Island. It forms part of the unincorporated Mason County community of Allyn-Grapeview. The island has a land area of 0.36755 km2 (90.82 acres) and a population of 119 persons, as of the 2010 census.

Peale Passage is a strait, in the southern of part of Puget Sound in the U.S. state of Washington. Entirely within Mason County, Washington, Peale Passage separates Hartstine Island from Squaxin Island. Peale Passage was named by Charles Wilkes during the Wilkes Expedition of 1838–1842, to honor Titian Peale, one of the expedition's naturalists.

The Squaxin Island Tribe are the descendants of several Lushootseed clans organized under the Squaxin Island Indian Reservation, a Native American tribal government in western Washington state. Historically, the ancestors of the Squaxin Island Tribe inhabited several inlets of the South Puget Sound. The Reservation was created in 1854 by the Treaty of Medicine Creek, comprising the entirety of Squaxin Island. Today, the reservation also includes several small parcels in the nearby area. Tribal members no longer reside on Squaxin Island itself, but 509 residents live on other Reservation and Off-Reservation Trust Land. Total tribal membership was at 1,022 as of 2010.

Squaxin Island is in the extreme southwestern part of Puget Sound in Mason County, Washington, United States. The island is an Indian reservation of the Native American Squaxin Island Tribe. A Washington state park on the island, by the same name, was closed and the land was returned to the Squaxin Tribe. The island's land area is 5.739 km2 (2.216 sq mi). There was no resident population as of the 2000 census. Squaxin Island is separated from Harstine Island, to the east, by Peale Passage. The island's name comes from the Lushootseed place–name sqʷax̌səd.