At first blush, it meant some other trapper ahead of them with a prior claim to the valley; a claim that the unwritten law would allow.

They followed it a mile.

It went striding along the shore at a great pace, sometimes running, and keeping down the west shore.
Then they found a place where he had sat down and broken a lot of clam shells, and again had hastened on.

But there was no mark of gunstock or other weapon where he sat; and why was he wearing boots?
The hunters rarely did.
For two miles the Indian followed with Rolf, and sometimes found that the hated stranger had been running hard.

Then they turned back, terribly disappointed.