Yes I remember seeing pygmy hippos in the large lake years ago. The oldest park souvenir guidebook I own was published in 1991 and it shows pygmy hippo. The next park guidebook I own was published in 2000 and it makes no mention of them. So they stopped some time in the 1990's, sorry I cannot be more specific.
Sadly it is many years since I was last in San Diego so I cannot comment from personal experience. However, after browsing through the Pygmy Hippopotamus Studbook (2008 edition) I cannot find any record of pygmy hippos in the San Diego Wild Animal Park after 1996.
I found a documentary length TV special on the opening of the Wild Animal Park back in 1972. Very interesting to see all that went into creation of the park initially and what it looked like at the time.
@Jambo: Oh my god, those good old days! Seeing the now closed WGASA running is kind of heartbreaking. On the other hand it is interesting to see, how the landscape has changed since. Specially the pedestrian parts of the park. They are now full of lush vegetation instead of sand and rocks as they were before. And funny, how the moderator was acting. Well, that were the 70ies where everything went a little more cozy Thank you so much for sharing this!
I am searching about Zoo Granby's history and discovered that a black rhino went to San Diego safari park and was exchanged with a giraffe. Later, he went to Cadwell Zoo, produced a calf in 2003, and died in 2013. I want to know if he produced a calf in the San Diego safari park? He was born on December 11 1979 in Granby, Sire? Dam ?. Then transferred to SDZ in March 1981 and then to SDZ-SP in May 1983.
According to the book "The Rhinoceros in Captivity" (Rookmaaker; 1998), "Cornelius" was born at Granby on 11th December 1979; parents "Bulley" and "Suzie". The book records that "Cornelius" fathered four calves at San Diego Wild Animal Park: "Jioni" born 12th September 1988 "Nakili" born 25th February 1990 "Jimma" born 29th November 1990 still born calf 1st December 1992
Unfortunately I don't have a copy of the Black Rhinoceros Studbook as that would probably answer your latest question. Frustratingly Rookmaaker's book doesn't state whether or not they were wild born. I suspect they probably were wild born otherwise, if they were captive bred, Rookmaaker would probably know the details about when and where they were born.