In the 1970's there were two sugar plantations still using a bit of steam, Pantaleon and Palo Gordo, both on the Pacific plain.  The first three pictures were taken in 1973 at Pantaleon (note the Shay). The second four pictures were taken at Palo Gordo in 1980.  Trucks seemed to be doing the bulk of the work even when the pix were taken so I doubt either of these steam operations lasted more than a few more years.