The Land Rover was driven by Mike Bowman during his family vacation to Costa Rica. As the family was originally from Dallas, Texas, the Rover was a rental. The car utilized a four-wheel drive transmission, the type commonly used for off-road vehicles. This is further illustrated in the car’s apparent ability to easily drive over both muddy roads and sandy beaches. It is currently unknown what specific model of Land Rover was utilized.
Jurassic Park by Michael Crichton page 11-12,16 (First Edition, Thirty Fourth printing)