In 1969--A replica of the "C.P. Huntington," an 1860 steam train owned by California Governor Leland Stanford replaces the old passenger train.
It is unknown what the OLD train was nor what year installed in the Zoo. This is/was not a so-called Amusement Park but a ZOO but contains 'Amusement Rides' such as the Miniature Train and 'unknown' what else since 1931. (nor it's prior years as the Zoo in Liberty Park)