USS Elk River in 1982
History
United States
Name	LSM(R)-501
Builder	Brown Shipbuilding Co.
Laid down	24 March 1945
Launched	21 April 1945
Commissioned	27 May 1945
Decommissioned	1 August 1946
Reclassified	1 October 1955
Recommissioned	January 1969
Decommissioned	October 1986
Renamed	Elk River
Namesake	Elk River
Stricken	13 August 1999
Homeport	San Diego
Identification	Hull number: IX-501
Motto	No Assignment We Shun, Till The Seas We've Won
Honours and awards	See Awards
Fate	Sunk as target, 24 February 2001
General characteristics
Class and type	LSM(R)-501-class landing ship medium
Displacement	758 t (746 long tons), light 993 t (977 long tons), attack 1,175 t (1,156 long tons), full
Length	206 ft 3 in (62.87 m)
Beam	34 ft 6 in (10.52 m)
Draft	5 ft 4 in (1.63 m), light 6 ft 9 in (2.06 m), attack 7 ft 9 in (2.36 m), full
Installed power	2,800 shp (2,088 kW)
Propulsion	2 × GM 16-278A diesel engines 2 × screws
Speed	13 knots (24 km/h; 15 mph)
Range	3,000 mi (4,800 km) at 13 kn (24 km/h; 15 mph)
Complement	6 officers, 137 enlisted
Armament	1 × single 5"/38 caliber gun 2 × twin Bofors 40 mm guns 4 × twin 20 mm AA guns 4 × 4.2 in (110 mm) mortars 10 × twin continuous loading 5-inch (130 mm) Ship-to-Shore rocket launchers

USS LSM(R)-501 was the lead ship of the LSM(R)-501-class landing ship medium built in 1945 for service in World War II. She was later converted into a test range support ship and renamed USS Elk River (IX-501). Her namesake was a Minnesota town named Elk River.^[1]

LSM(R)-501 was laid down on 24 March 1945 at Houston, Texas, by the Brown Shipbuilding Company. She was launched on 21 April 1945 and commissioned on 27 May 1945.^[2]

LSM(R)-501 served in the Pacific before and after the Japanese Surrender in September 1945. This vessel was designed to carry both shorter range guns and rocket launchers to deliver large volumes of fire in short periods. Decommissioned on 1 August 1946 at Astoria, the vessel was laid up in the reserve fleet Columbia River Group.^{[citation needed]}

Renamed and redesignated USS Elk River (IX-501) on 1 October 1955, she was converted into a test range support ship at Avondale Shipyards and at San Francisco Bay Naval Shipyard.^{[citation needed]}

In November 1967, she was underway off Long Beach, California in support of the SEALAB III Project.^[3]

In early 1982, Elk River began her installation of the Mk.14 CCSDS until the summer of that year.^[4] The ship later served as a barracks craft in October 1986.

Struck from the Naval Register in August 1999, Elk River was sunk as a target in February 2001.^[1]

A model of USS Elk River (LSM(R)-501, later IX-501) is on display in the Cold War Gallery, Building 70.^[5]

• 
  LSM(R)-501 after her conversion in 1955
• 
  Elk River and SEALAB III drawing, 1968

• Navy Meritorious Unit Commendation
• American Campaign Medal
• World War II Victory Medal
• National Defense Service Medal

• Naval History and Heritage Command: USS Elk River (LSMR-501, later IX-501)
• NavSource Online: Elk River (IX-501)
• Naval Vessel Register: ELK RIVER (IX 501)

v t e LSM(R)-501-class landing ships medium (rocket)
LSM(R)-501 / Elk River LSM(R)-502 / Escalante River LSM(R)-503 / Flambeau River LSM(R)-504 / Gila River LSM(R)-505 / Grand River LSM(R)-506 / Green River LSM(R)-507 / Greenbrier River LSM(R)-508 / Gunnison River / Targeteer LSM(R)-509 / Holston River LSM(R)-510 / James River LSM(R)-511 / John Day River LSM(R)-512 / Lamoille River LSM(R)-513 / Laramie River LSM(R)-514 / Maurice River LSM(R)-515 / Owyhee River LSM(R)-516 / Pearl River LSM(R)-517 / Pee Dee River LSM(R)-518 / Pit River LSM(R)-519 / Powder River LSM(R)-520 / Raccoon River LSM(R)-521 / Rainy River LSM(R)-522 / Red River LSM(R)-523 / Republican River LSM(R)-524 / Saint Croix River LSM(R)-525 / St. Francis River LSM(R)-526 / St. Johns River LSM(R)-527 / St. Joseph's River LSM(R)-528 / St. Mary's River LSM(R)-529 / St. Regis River LSM(R)-530 / Salmon Falls River LSM(R)-531 / Smoky Hill River LSM(R)-532 / Smyrna River LSM(R)-533 / Snake River LSM(R)-534 / Thames River LSM(R)-535 / Trinity River LSM(R)-536 / White River
Other operators  German Navy Otter (ex-Smyrna River) Natter (ex-Thames River)  Republic of Korea Navy Si Hung (ex-St. Joseph's River)  Panamanian Public Forces ex-Smoky Hill River
Preceded by: LSM(R)-401 class Followed by: None
List of United States Navy amphibious warfare ships