Further down they came to a place where the only possible track lay along the bottom of a three-hundred-foot slope, steeper than the roof of a house and thick in snow, which glared blinding white in the morning sun. The opposite slope was covered with the amazingly thick forest which they had seen from above.
"Go keerful," said Rube. "'Twouldn't take a great deal to start a snowslide down them rocks."
"Seems as if something had been falling already," said Roger suddenly. "Look at these pits in the snow."
He pointed to a hole in the snow. It was circular and about two feet deep.
"Now that's strange," exclaimed Nick. "There's a whole row of 'em."
Rube looked at the queer marks, grunted, and shook his head. He hadn't a notion what they were, but did not like to betray his ignorance to the boys.
"Reckon best not talk," he growled. "Don't take much to start snow a-sliding."
For the next half mile no one spoke. Twice more Roger noticed a series of the same queer marks in the snow. Also in two places there seemed to be regular roads beaten back into the thick underbrush of the snowclad forest on their right. He did not pay much attention. His eyes were fixed on the tree trunks.
Suddenly he gave a shout.