The Spaniards intended to remain of the river to mine. Upon reflection, and believing that troops were seen in that direction coming from Santa Fe, or in that direction, they could only be Confederate troops, comiing for one purpose, viz, Yuma. They could come through what is know as the Zani Pass, between the Sierra Blanca and Mogollon Mountains, striking the Salina River and following it down to the Pimas. On referring to the map of Arizona and Sonora and the adjoining territory known as German Ehrenberg`s map [issued in 1858 from his private notes], and those of Colonel Gray, Major Heintzelman, Lieutenant Parke, and others, I find a train laid down running through that pass by the Pimas to San Xavier, nine miles south of Tucson. If the troops are our own, they would, is successful at Craig, come that trail, perhaps, to cut off troops at Tucson. IIf Sibley bas given battle at Craig, and was at Tucson, foloow up in that direction direct or take the trail mentioned above, to avoid being discovered, with a view of reaching Yuma before re-enforcements could reach here. From where he could strike the Gila, following the Salina to ots mouth, he would not have over ten days' forced marches. They are provided with pack animals only. Mr. Weaver knows the county well, and assures me that they can not croos anywhere but at that point. He has gon up himself to follow in that direction for information for me, and I will hear from him in seven days. I have thought it best to inform you of this immediately. Shouls they be Confederate troops, we will give them a fight from Grinnel's all the way down. I respectfully submit this to the colonel commanding for what it is worth. I sent Mr. George Martin into Sonora last night. He will push his scouts through the Papagos toward Tucson and Pimas, and assures m that in five days he can give me positive information about troops being there and the number of them.

Very respectfully, your obedient servant,

EDWIN A. RIGG,

Major First Infantry California Volunteers, Commanding.

HUMBOLDT MILITARY DISTRICT,

Fort Humboldt, March 27, 1862.

Major R. C. DRUM,

Assistant Adjutant-General, Department of the Pacific:

MAJOR: Such was the state of the trails [being almost impassable]

that the mule owners employed to transport the supplies for the threecompanies I was sending to the new posts found it impossiple to get their miles here and in readiness to start until the 10th instant. On that day Conpanies F and K, Second Infantry California Volunteers, commenced their march, and although every exertion was made to get on, it took them both about twelve days to arrive at their posts, distance from this post only thirty and thirty-five miles, respectively, Even this was accomplished by leaving behid the greater part of their post, about fifty miles hence. Hearing that some of the men of Captain Heffernan's company [K, Second Infantry California] had assaulted their officers, I immediately followed them, accompanied by Lieutenant Hanna. I came up with them about five moles beyond Areata. Two