As has already appeared, the trappers were on the banks of the Colorado at the time this affair happened. They continued their work on it, descending the south side until they reached tide water, when they changed their camp on to the Gila, and continued trapping up this river as far as the mouth of the San Pedro. Near the outlet of this river, they discovered a large herd of horses and mules; on a closer examination, they found that they were in the possession of a band of Indians who had formerly given them some of their gratuitous hostilities. Not having forgotten their former troubles with these people, they determined to pay them off in their own coin by depriving them of the herd. A short search sufficed to discover the Indian camp. Without waiting an instant, they put their horses to their speed and charged in among the huts. The Indians were so completely taken by surprise, that they became panic-struck and fled in every direction. They, however, rallied somewhat, and a running fight commenced which lasted some time, but which did not change matters in favor of the Indians. The entire herd fell into the possession of the trappers. On the same evening, after the men had wrapped themselves up in their blankets and laid down for a sleep, and while enjoying their slumbers, a noise reached their ears which sounded very much like distant thunder; but a close application of the sense of hearing showed plainly that an enemy was near at hand. Springing up, with rifle in hand--for generally in the mountains a man's gun rests in the same blanket with himself on all sleeping occasions--they sallied forth to reconnoitre, and discovered a few warriors driving along a band of at least two hundred horses. The trappers comprehended instantly that the warriors had been to the Mexican settlements in Sonora on a thieving expedition, and that the horses had changed hands with only one party to the bargain. The opportunity to instill a lesson on the savage marauders was too good to be lost.