It is a sultry day, early in July, and the sun is going westward through a fleet of white, wind-driven clouds that send a host of deep shadows sweeping and chasing over the wide prairie. Northwards the view is limited by a low range of bluffs, destitute of tree or foliage, but covered thickly with the summer growth of bunch-grass. Southward, three miles away at least, though it seems much less, a similar range, pierced here and there with deep ravines, frames the picture on that side. Midway between the two ridges and fringed with clumps of cottonwood and willow, a languid stream flows silently eastward and is lost, with the valley, in the dim distance. Out to the west in long, gradual curve the southward range veers around and spans the horizon. Midway across this monotone of landscape, cutting the stream at right angles, a hard prairie road comes twisting and turning out of one of the southern ravines and, after long, gradual dip to the ford among the cottonwoods, emerges from their leafy shade and goes winding away until lost among the "breaks" to the north. It is one of the routes to the Black Hills of Dakota,--the wagon road from the Union Pacific at Sidney by way of old Fort Robinson, Nebraska, where a big garrison of some fourteen companies of cavalry and infantry keep watch and ward over the Sioux Nation, which, one year previous, was in the midst of the maddest, most successful, war it ever waged against the white man. That was the Centennial year--'76. This is another eventful year for the cavalry,--'77; for before the close of the summer even the troops so far to the southeast are destined to be summoned to the chase and capture of wary old Chief Joseph,--the greatest Indian general ever reared upon the Pacific slope,--and even now, on this July day, here are cavalrymen at their accustomed task, and though it is five years since we saw them under the heat and glare of the Arizona sun, there are familiar faces among these that greet us.