When did the hotel that hosted the recording of Farewell close?
Farewell (The Supremes album):  The album was recorded over the course of the group's final engagement together at the New Frontier Hotel and Casino in Las Vegas, Nevada, including the final night on January 14, 1970. New Frontier Hotel and Casino:  It was the second resort that opened on the Las Vegas Strip and operated continuously from October 30, 1942 until it closed on July 16, 2007.
July 16, 2007