Cavalry, commanding the detachment of cavalry under my command, comprising thirty enlisted men of Company D, First Oregon Cavalry, marched from this place on the morning of the 6th instant. Passing out of the eastern end of Summit Valley, a plain situated near the source of Selvie's River or Cricket Creek, and about sixty-five miles north of Harney Lake, I passed over a succession of timbered hills, gradually ascending toward the east a distance of four or five mules, and the joining to several irregular chains of mountains, the most prominent of which lay to the north. Taking this prominent ridge I found it to be the dividing range between Canyon Creek to the north and the East Fork of Selvie's River to the south. The general course of this high divide as east-northeast and west-southwest, and it leads directly toward Malheru Route, the highest point of the mountains, at the head of John Day's River. About three miles after striking the ridge our route intersected a large trail which comes out of the great defile of Canyon Creek, and runs almost due south in the direction to Steen's Mountain, east of Harney Lake. The guide, an old trapper, who is practicably acquainted with the country, thinks that this trail was formerly used by the Indian tribes of the Umatilla and Walla Walla Rivers in coming to the mountains of this vicinity in search of game. It may, however, be a thoroughfare to the Harney Lake country. It has not been recently traveled. Following along the divide our route was quite practicable, though rough in many places from rocks and fallen timber. There are two steeps precipices of perhaps 300 feet each, about sixteen miles from Camp No. 38. From the last precipice it is six miles to the source of the East Fork of Selvie's River in a canon a few miles southeast of Malheur Butte. Here the detachment was encamped for the night after a march of about twenty-two miles. Camping facilities were sufficient.

On the evening of the 7th with some difficulty from the steepness of the ascent and rocky nature of the mountain, I moved up two miles to the top of the range. There is a fine spring here with some mountain grass surrounding it on the hill-side. The range here is quite rugged, its northern face forming a cove in the shape of a horseshoe of several miles in circumference. The walls of the cover are nearly perpendicular, are composed of basalt rock, are about 1,000 feet in height, support several very larg beds of snow, and rest their base upon a large table-land. On this table-land, thousands of feet above John Day's River, the brooks from the walls of the cove form a lake about one and a quarter miles long and half a mile wide. The lake is bordered by rock and a large grove of pine surrounds it. A larg stream issue from the lake and runs into John Day's River. Malheur Butte occupies the northwestern end of the cove three miles distant from its center. Leaving the animals at the spring in charge of one platoon, with the other I went to the summit of the butte. The ascent was steep and rocky. The buttes is composed of trap rock. It commands a fine view of the country for more than 100 miles around. The Middle Ford of John Day's River has its source in the mountains immediately connected with the battle, to the east a few miles; Canyon Creek five miles to the southwest; Selvie's River or Cricket Creek (East Fork) three miles south-southwest. One fork of Malheur River heads directly east and runs east, and another tributary heads about five miles southeast; runs south perhaps fifteen miles, where it is joined by a stream coming from the west and turns east. All the intermediate country about these streams is mountainous and covered with fine timber, except two small valleys on Selvie's River, one of the tributary of Malheur,