Owner Frank Mee said he was closing the park, but it was not for sale.
He said the park had been making money and was "very popular".
"Everyone is going bankrupt in Queenstown, but we are not. . . we're just getting too old, so we're giving up," he said.
Mr Mee was born in 1922 and he, and his wife Jean, opened the park in 1970.
It was granted a zoo licence in 1971.
Over time, the park grew from just seven red deer to nearly 1000 red and fallow deer, alpaca, Himalayan tahr, llama, bison, yaks, donkeys, goats, miniature horses, kune kune pigs and ducks.
The park was used as a location for the Wolverine (X-Men) movie and offered some of the most spectacular views in the area, he said.
He said the park was cheap to run because entry was $20 by way of an automatic toll gate.
Dispensers offered tourists a tin of nuts for $2 to feed the animals.
However, the park had been vandalised recently, with visitors breaking three dispensers and pulling out signs.
Deer Park Safaris Ltd ran guided tours through the park.
Driver Brian Mitchell, from Arrowtown, said the closure was "a bolt out of the blue".
He was told on Monday last week he was out of a job because the park was closing.
"It's a bit of a shame," he said.
Company director Antony Bush was "shattered" by the sudden decision, Mr Mitchell said.
Mr Bush could not be contacted for comment.