In the winter of 1947, Peter Riddle passed away and Shannon was sold at public auction. Fetching the highest price ever paid for a thoroughbred at auction, he went to the Randwick yard of trainer Frank Dalton for new owner W.J. Smith. He raced four times in Smith's colours for two wins and two seconds, but as a burgeoning seven year old Shannon would not be able to recoup his purchase price. Smith promptly shipped the horse to California, heralding a rough and rocky time for the sensitive Shannon.
Though it took Shannon many months to find his running shoes, when he finally did he became a lightning hit across California, winning the San Francisco County Handicap in track record time, the Argonaut Handicap, Hollywood Gold Cup, Forty-Niners (equaling the American record), Golden Gate Handicap (setting a new American record and equaling the world mark), and San Francisco Handicap, setting a new track record.