Thanks for the info on Mario Miraglia. We wrote to the email provided and received a reply from his daughter, Anto: antomiraglia17@gmail.com
We tried to book Mario for a 3 hour tour of the National Park (price quoted for 3 hours at $140). Unfortunately for us, Mario was already booked on the day we needed him.
We then checked out getting a Remis ( a driver reserved in advance). It was easy to make a reservation by email and the price quoted for 3 hours was 59,000 AR pesos (~$60). www.remiscar.com.ar | transfers@remiscar.com.ar
But then we heard from Mario's daughter again who referred us to cab driver Diego Joel Giles, who speaks English. The price for 3 hours in the National Park was $140. We booked him and he waited at the cruise port gate for us with a sign. He took us exactly to the places we wanted and could talk to us easily. We spent 4 hours with him and were very pleased. Diego can be reached at +54 290 146 4119 or diegojoelgiles@yahoo.com