Moccasin's dam, the British-bred Rough Shod, was a great success[2] at stud, producing Ridan, Lt. Stevens (Palm Beach Stakes)[3] and the broodmare Thong (ancestor of Sadler's Wells).
[10] In the following month, she appeared to have decided the title of U.S. Champion 2-Yr-Old Filly when she won the Matron Stakes at Aqueduct Race Track, finishing six lengths clear of her opponents in a time of 1:11.6.
[11] A challenger emerged in the form of Priceless Gem, who defeated Buckpasser at Aqueduct, but an injury ruled her out of a showdown with Moccasin in the Selima Stakes.
[12] She completed her unbeaten first season in November when she recorded a two and a half-length win over Lady Pitt in the Gardenia Stakes at Garden State Park.
[13] In early 1966, Moccasin was expected to challenge the colts in the Kentucky Derby, and there were hopes that she might emulate Regret, the last filly to win the race more than fifty years earlier.
In August, Moccasin showed some signs of a return to form[17] by winning a division of the seven furlong Test Stakes, but it was her only notable success of 1966.