Complex sentence: On 15 June 1986, "Mascoutah" was withdrawn from service and transferred to the Maritime Administration and placed in the National Defense Reserve Fleet, then transferred to the Saint Lawrence Seaway Development Corporation in 1989.
Split into simpler sentences: On 15 June 1986, "Mascoutah" was placed out of service and transferred to the Maritime Administration. Other sources indicate that "Mascoutah" was placed in the National Defense Reserve Fleet in 1986 and transferred to the Saint Lawrence Seaway Development Corporation in 1989.