McCandless had driven his car to the Lake Mead National Recreation Area in July, and against posted regulations, had driven it off road in the park and had pitched a campsite. A few days later, flash flooding almost washed away his campsite, and his car’s engine got so wet he couldn’t get it to start. Because he wasn’t supposed to have driven off-road, he couldn’t get help from the rangers, and so he left the car with a note saying whoever can get the car to work can keep it.
Between these word choices, I would say tracks...as in traces/tracks one's steps...The other's don't really match the meaning of the word "traces"...hope this helps!
