On Isla Nublar, there were a various service roads that the workers used apart from the main tour. The East Road began at the Visitors’ Center, and extended all the way to the East Dock, the distance of the road being about a mile. It was this road that Dennis Nedry took in his attempt to deliver the stolen embryos in the cryogenic container to the East Dock. However, he took a wrong turn down a dead end, his suspicion about it being a wrong turn confirmed when Robert Muldoon and Donald Gennaro traveled from the East Road to discover his corpse.
Jurassic Park by Michael Crichton page 194, 288 (First Edition, Thirty Fourth printing)