the 2nd of March [April?] on the road by the copper mines to San Serain or Tucson. Senor Oroscco goes, to-night, home with Kilbrige to do the same thing. He cannot act personally, being in an official position, but will have it done, so that what he reports can be depended on. He urges the district commander, or some one else clothed with the proper authority, to write to Pesqueira. Both he and Brdy assure me that the Sonorans are, almost to a man, warm friends of our Govenrment, and would not only cheerfully but faithfully perform any request made of them. Senor Orosco's integrity is indorsed by every one here, and all Somorans speak of him in high terms. He furnished fresh animals to Buckner and a guide [the Dutchman] mentioned by Brady, but sent me word that the sessenger talked too much. It would not be safe for him to go in that direction again. I have written to Clymer to conceal his powder or haul it to Antelope Peak for safety [where it will be safer].

Very respectfully, your obedient servant,

EDWIN A. RIGG,

Major First Infantry California Volunteers, Commanding.

[Inclosure.]

SONOITA, March 14. 1862.

Major E. A. RIGG,

First Regiment California Volunteers, Commanding Fort Yuma:

DEAR SIR: I write to inform you of the news here, according to promise. I saw a man a little while ago who has just come in from the Cababi mines. He informed me that three days ago he conversed with a man just through from Tucson, who came throught with Captain Hunter's party from Mesilla, and this person seemed to be pretty well posted in regard to everything in Western Arizona. They are perfectly aware in Tucson of there being a large quantity of powder at the copper mines, and that the superintendent is a Union man, and there is some talk of their coming over and taking it. I am very much afraid they will, as it is a big inducement. I know that there is very near a ton of powder there. Fortunately an American came down today from the copper mines and goes back tomorrow. I have advised him to tell Frank Clymer to hide the powder somewhere about the mine, only leaving a keg or two in the magazine, and to tell the secessionists that he has sold the balance, for of he had none at all they might suspect that he dah hidden it and resort to severe measures to make him disclose. The Mexicans are very much frightened here, and have plenty of reasons for being so. In the conversation that this man had with this man of Captain Hunter's party he seemed to be very well posted about the stock at this ranch, and as they are saldy in want of horses they may make an in road in this place. However, pretty much everything depends in the result of Colonel Reily's missiion to the Governon. As you have already learned, Colonel Reily has gone to Hermosillo to make some arrangements with the Governor. What they are, nobody knows, but they can be easily guessed at. I suppose Colonel Reily will promise to protect the frontier and keep the Apaches out of Sono me at present as if they would have a pretty lively time of it in protecting themselves. The Mexicans all feel confident that Pesqueira, the Governor, will enter into no arrangement whatever with them, and if he does not, why then they will certainly make a foray on this ranch, as there are a good many horses here and plenty of cattle. They also made inquiries about Juito