DEPARTMENT OF THE INTERIOR,
Washington, September 8, 1874.

Sir:
I acknowledge the receipt of your letter of the 27th ultimo, referring to associations that are forming for the invasion of that part of the Territory embracing the Black Hills, notwithstanding existing treaties with the Sioux Indians, and requesting such suggestions for the guidance and benefit of citizens of the Territory as may be considered appropiate by the Department, and in reply would say: by the second article of the treaty between the United States and different tribes of Sioux Indians, concluded April 29, 1868, (Statutes, vol. 15, p. 636,) "the United States agrees that the following district of country, to wit, viz: commencing on the east bank of the Missouri river where the forty-sixth parallel of north latitude crosses the same; thence along low-water mark down said east bank to a point opposite where the northern line of the State of Nebraska strikes into the river, thence west across said river and along the northern line of Nebraska to the one hundred and fourth degree of longitude west from Greenwich, thence north on said meridian to a point where the forty-sixth parallel of north latitude intercepts the same, thence due east along said parallel to the place of beginning; and in addition thereto, all existing reservations on the east bank of said river shall be, and the same is, set apart for the absolute and undisturbed use and occupation of the Indians herein named, and for such other friendly tribes or individual Indians as from time to time they may be willing, with the consentof the United States, to admit amongst them; and the United States now solemnly agrees that no persons except those herein designated and authorized so to do, and except such officers, agents, and employees fo the Government as may be authorized to enter upon Indian reservations in the discharge of duties enjoined by law, shall ever be permitted to pass over, settle upon, or reside in the Territory described in this article, or in such territory as may be added to this reservation for the use of said Indians, and henceforth they will and do hereby relinquish all claims or right in and to any portion of the United States or Terriotories, except such as is embraced within the limits aforesaid, and except as hereinafter provided.
The foregoing section prescribes who shall be allowed to enter this territory so set apart for the Indians and expressly states that none others shall be permitted to pass over, settle upon, or reside therein. The only power to alter this provision is that which made the treaty, and then it must be done with the consent of the Indians. What is known as the late "exploring expedition" of General Custer was merely a military reconnaissance of the country for the purpose of ascertaining the best location if in the future it should become necessary to establish there a military post.
On the 22d of June last, in a letter to this Department, the Honorable the Secretary of War wrote on this subject as follows:
"It is well known to the Department, that at various times the settlers in the adjacent country have comtemplated explorations to the Black Hills, and the Department has uniformily discountenanced such movements; but it has now almost become a military necessity that accurate knowledge should be posessed by the Army as to this portion of our Territory, and for that purpose only is the present expedition undertaken."
The question of opening up this country to settlement rests with Congress, and until action has been taken by that body, this Department has no discretion in the matter, but is required and will endeavor to prevent any violation of the provisions of the treaty before mentioned.
For the reasons herein set forth, all applications for permission to visit the Black Hills country will be denied.
Very respectfully, your obedient servant,

B. R. COWEN,
To Acting Secretary
Gov. J. L. Pennington,
Yankton, Dakota