Frank scrambled eagerly to the crest of the ridge on which his friend was perched.
They were in the heart of that picturesque wonderland about the head waters of the Yellowstone River, known as the National Park.
Frank had a camera slung at his back, and for three days he had been trying to get a "shot" with it at a buffalo, having been told there was a small herd of the nearly extinct creatures somewhere in that region.
Neither of the boys had the least desire to kill one of the animals, and a "shot" with the camera at close range would have satisfied them.
And now, in the grassy valley below them, at a distance of half a mile, they could see five of the animals they sought. The creatures were grazing, with the exception of the largest of the herd, which seemed to be standing on guard, now and then snuffing the wind.
The moment Frank saw them he clutched his companion, drawing him backward and down behind some bowlders.
"Pwhat's th' matther wid yez?" spluttered Barney, in surprise.
"If we expect to get near enough to photograph those creatures, we must get out of this right away."
"Whoy?"
"Did you observe the old fellow who is standing on guard? Peer out and you can see him. He is headed this way."