Basic island data


Location: southern Puget Sound, WSW of Tacoma, NW Washington


Coordinates: 47°12’40” N, 122°41’20” W [1]


Area: 6.9 sq mi / 18.0 sq km [4]


Highest point: Hyde Point Head, 320+ feet [2]


Population: 1,516 (2000) [3]


Alternate names:

– former alternate: Duntze Island [5]

– former: McNeil’s Island [7]




– 1. National Map Viewer, US Geological Survey.

– 2. “Hyde Point Head, Washington,”, viewed February 2010.

– 3. U.S. Census Bureau, via “McNeil Island,”, viewed February 2010.

– 4. “McNeil Island Corrections Center,” Washington State Department of Corrections, viewed February 2010.

– 5. “Feature Detail Report for: McNeil Island,” Geographic Names Information System, US Geological Survey., viewed February 2010.

– 6. Harvey Manning, Footsore 4: Walks and Hikes around Puget Sound (Seattle: The Mountaineers, 1979), 184.

– 7. Daryl C. McClary, “McNeil Island and the Federal Penitentiary, 1841-1981,”, April 17, 2003.

– 8. “The Special Commitment Center Program,” Washington State Department of Social & Health Services, March 24, 2009.

– 9. “Special Commitment Center Total Confinement Facility,” Washington State Department of Social & Health Services, March 24, 2009.

– 10. “McNeil Island Corrections Center History,” Washington State Department of Corrections, viewed February 2010.






McNeil Island


McNeil Island is a 6.9-square mile island in southern Puget Sound, in northwest Washington.  It is the site of the McNeil Island Corrections Center, and is the only unbridged prison island left in North America.  About 3/4ths of the island is a wildlife refuge.[10]


The island’s population is either prisoners or employees of penal institutions and their dependents.  In addition to the state prison, it is also the site of the Special Commitment Center, a detention and treatment facility for sexually violent predators.[8]


McNeil_Island.jpgThe island is compact, with the only major indention Still Harbor on the northeast side.  The terrain is rolling, peaking at more than 320 feet at Hyde Point at the eastern end of the island.  Land use is divided between blocks of forest and agricultural land.  Butterworth Reservoir is a large lake at the center of the island, and the island also has several smaller reservoirs and ponds.


McNeil Island is east of the Key Peninsula, north of Anderson Island across Balch Passage, and separated from Fox Island to the northeast by Carr Inlet.  Gertrude Island lies at the mouth of Still Harbor.


The island was named in 1841 by Lt. Wilkes of the United States Exploring Expedition for Capt. William Henry McNeill of the Hudson Bay Company.  It was settled by the Meeker family in 1853, but they left after about a year.[7] 


The federal government acquired 27 acres on the island in 1870, and opened a federal prison in 1875.[4]  Civilian settlement began on the island in the 1880s, and there was a substantial community with schools and a store by 1900.  The prison was greatly expanded in the early 20th century, and had about 1,000 prisoners in 1930.[7]  The last civilian inhabitants unaffiliated with the prisons left the island in 1936.[6]


Notable federal prisoners included Robert Stroud (“The Bird Man of Alcatraz”), and Charles Manson.[7] 


A prison farm was designated a Federal Work Camp in 1948, and a large agricultural operation there employed about 1,000 prisoners.[7]


In 1981, the federal prison was shut down, and Washington state took over the facility.   [7]  A confinement facility for violent sexual offenders opened on the island in 2004.[9]


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--------------------------- Copyright Joshua Calder

Contact Joshua Calder at calder.josh[at] with questions or suggestions. 

island geography / biggest island