First of her class to be launched, Kootenay was built at Burrard Dry Dock, Vancouver, and commissioned there on 7 March 1959. After working up, she was transferred to the east coast. On 23 October 1969, while in European waters, she suffered a gearbox explosion that killed 9 crewmen and injured 53 others. She was towed to Plymouth - part of the way by Saguenay and then to Halifax by a salvage tug. It was the RCN's worst-ever peacetime accident. While she was under repairs, it was decided to convert her to an IRE, in which guise she was re-commissioned on 7 January 1972. Transferred to the west coast, she arrived in Esquimalt on 12 February 1973. On 1 June 1989, Kootenay collided in fog off Cape Flattery with the M.V. Nord Pol, sustaining a sizeable gash in her bow, which was replaced with a matching section from Chaudiere. From 3 to 7 June 1990, Kootenay visited Vladivostok as part of a Canadian Task Group, the first to do so since World War II. In the summer of 1994 she took part in enforcing UN sanctions against Haiti. Her final trip found her off Uruguay for a two month naval exercise called UNITAS. On 18 December 1996, she was paid off and, on 6 November 2000, towed out of Esquimalt to be sunk as an artificial reef off Puerto Vallarta, Mexico, though this was likely never completed. Her present whereabouts is vague.
Modified as Improved Restigouche Class 1970-1972. DELEX refit in 1984.