"Niagara Falls" participated in the Tanker War phase of the Iran–Iraq War supporting Operation Prime Chance and Operation Earnest Will. In one near action the "Niagara Falls" crossed paths with an Iranian minelayer and during a tense hour "Niagara Falls", prepared to defend herself. There was no exchange of fire, the intelligence on the minelayer was relayed by Captain Gay to the fleet and the Iranian ship was subsequently intercepted by US Navy combatant forces. "Niagara Falls" often visited Bahrain, Fujiarah, Muscat, and the obligatory Masirah Airhead Evolutions during this time.