What was Buck's route in Chapter 5 after he and the group are bought by Charles and Hal?

The route the dogs were taking was familiar, as they'd already run the distance between Saltwater and Dawson four times.

Late next morning Buck led the long team up the street. There was nothing lively about it, no snap or go in him and his fellows. They were starting dead weary. Four times he had covered the distance between Salt Water and Dawson, and the knowledge that, jaded and tired, he was facing the same trail once more, made him bitter.

how many previous times had buck covered the distance between Salt Water and Dawson

How many previous times had Buck covered the distance between Salt Water and Dawson