‘Tremont’ was coined in the 19th century, by tradition from three local ‘mounts’.
The name did not come from a colonial settlement. According to NYC Parks, the area was known as Upper Morrisania until the 1850s, when postmaster Hiram Tarbox found his mail mixed up with that of nearby Morrisania. Legend has it that he renamed it Tremont, ‘tre’ (three) for the hills of Mount Eden, Mount Hope and Fairmount.