ere with a picket at the farther end of the valley,
where the creek made its exit, rushing through a narrow and winding
gorge. There was a level space on either side of the creek, but it was
too narrow for horsemen, and, clogged as it was with snow, it looked
dangerous now for those on foot too. Nevertheless, the picket kept a
close watch. Dick and his friends were aware that guerrillas knew much
of the craft and lore of the wilderness, else they could never have
maintained themselves, and they did not cease for an instant to watch the
watery pass.

They were joined very soon by Shepard, upon whose high boots snow
was clinging to the very tops, and he said when Dick looked at him
inquiringly:

"I see that you're an observer, Mr. Mason. Yes, I've been out on the
mountainside. Colonel Winchester suggested it, and I was glad to do as
he wished. It was difficult work in the snow, but Mr. Reed, our guide,
was with me part of the time, and we climbed pretty high."

"Did you see anything?"

"No footsteps. That was impossible, because of the falling snow, but I
think our friends, the enemy, are abroad in the mountains. The heavy
snow may have kept them from coming much nearer to us than they are now."

"What makes you think so?"

Shepard smiled.

"We heard sounds, odd sounds," he replied.

"Were they made by a whistle?" Dick asked eagerly. Shepard smiled again.

"It was natural for you to ask that question, Mr. Mason," he replied,
"but it was not a whistle. It was a deeper note, and it carried much
farther, many times farther. Mr. Reed explained it to me. Somebody with
powerful lungs was blowing on a cow's horn."

"I've heard 'em. They use 'em in the hills back of us at home. The
sound will carry a tremendous distance on a still night like this.
Do you think it was intended as a signal?"

"It's impossible to say, but I think so. I think, too, that the bands--
there were two of them, one replying to the other--belong to the Slade
and Skelly outfit. Skelly has lived all his life in the mountains and
Slade is learning 'em fast."

"Then it behooves us to be watchful, and yet more watchful."

"It does. Maybe they're attempting an ambush, with which they might
succeed against an ordinary troop, but not against such a troop as this,
led by such a man as Colonel Winchester. Hark, did you hear that noise?"

All of them listened. It sounded at first like the cow's horn, but they
concluded that it was t