Deep in the Wyoming hills lay a valley watered by a stream that ran down from Cheyenne Pass; a band of Sioux Indians had an encampment there. Viewed from the summit of a grassy ridge, the scene was colorful and idle and quiet, in keeping with the lonely, beautiful valley. Cottonwoods and willows showed a bright green; the course of the stream was marked in dark where the water ran, and light where the sand had bleached; brown and black dots scattered over the valley were in reality grazing horses; lodge-pole tents gleamed white in the sun, and tiny bits of red stood out against the white; lazy wreaths of blue smoke rose upward.

The Wyoming hills were split by many such valleys and many such bare, grassy ridges sloped up toward the mountains. Upon the side of one ridge, the highest, there stood a solitary mustang, haltered with a lasso. He was a ragged, shaggy, wild beast, and there was no saddle or bridle on him, nothing but the halter. He was not grazing, although the bleached white grass grew long and thick under his hoofs. He looked up the slope, in a direction indicated by his pointing ears, and watched a wavering movement of the long grass.

It was wild up on that ridge, bare of everything except grass, and the strange wavering had a nameless wildness in its motion. No stealthy animal accounted for that trembling—that forward undulating quiver. It wavered on to the summit of the ridge.

What a wide and wonderful prospect opened up to view from this lofty point! Ridge after ridge sloped up to the Wyoming hills, and these in turn raised their bleak, dark heads toward the mountains, looming pale and gray, with caps of snow, in the distance. Out beyond the ridges, indistinct in the glare, stretched an illimitable expanse, gray and dull—that was the prairie-land. An eagle, lord of all he surveyed, sailed round and round in the sky.

Below this grassy summit yawned a valley, narrow and long, losing itself by turns to distant east and west; and through it ran a faint, white, winding line which was the old St. Vrain and Laramie Trail.

There came a moment when the wavering in the grass ceased on the extreme edge of the slope. Then it parted to disclose the hideous visage of a Sioux Indian in war paint. His dark, piercing, malignant glance was fixed upon the St. Vrain and Laramie Trail. His half-naked body rested at ease; a rifle lay under his hand.

There he watched while the hours passed. The sun moved on in its course until it tipped the peaks with rose. Far down the valley black and white objects appeared, crawling round the bend. The Indian gave an almost imperceptible start, but there was no change in his expression. He watched as before.

These moving objects grew to be oxen and prairie-schooners—a small caravan traveling east. It wound down the trail and halted in a circle on the bank of a stream.

The Indian scout slid backward, and the parted grass, slowly closing, hid from his dark gaze the camp scene below. He wormed his way back well out of sight; then rising, he ran over the summit of the ridge to leap upon his mustang and ride wildly down the slope.