Mr. Justice Field,,

after stating the case, delivered the opinion of the court.

The exceptions taken in the District Court were fully considered and answered by the Supreme Court of the territory in a clear and satisfactory opinion. The objections to the sufficiency of the evidence to justify the findings of fact cannot be heard her©,; .they were matters for consideration only in the courts below, Of. the numerous assignments of error presented to us, we deem only three of sufficient importance to require special consideration. They are:

1. That the judgment is not sustained by the pleadings;

*399 2. Thai the articles of incorporation of the plaintiff were-admitted in evidence without due authentication; and,

3. That evidence of acts of the predecessors of the plaintiff in locating and developing the Caledonia lode prior to the relinquishment of the Indian title'to the United States was improperly admitted.

1. There would be some force in the objection that the judgment is not sustained by the pleadings, if the amendment joining Mahan as a codefendant with Noonan could not be read as á part of them. The judgment is against him' as well as against Noonan, and there must appear somewhere in the record allegations by which it can be supported. It would have been the better course, when the order was entered that1 Mahan be joined as a codefendant, for the attorneys of the plaintiff to have had his name at.once inserted in the complaint, with such other changes as to make the allegations apply to him. That such changes might have been made by consent of parties, without the formality of suspending the trial, and filing a new complaint, and waiting for an' answer to it, there can be no doubt; and when thus made, the parties would be estopped from any subsequent objection to them. & provision of the Code of Civil Procedure of Dakota vests ample authority in the court to make changes of this character in furtherance of justice. Its language is: “ The court may, before or after judgment, in furtherance of justice, and on such terms as may be proper, amend any pleadings, process or pro.ceeding, by adding or striking out the name of any party; or by correcting a mistake in the name of a party, or a mistake in -any other respect, or by inserting other allega^ tions material to the case, or, if the amendment does not change substantially the claim or defence, by conforming the proceeding or pleading to the facts proved.” § 142.

The trial continued after the amendment, the defendant Mahan participating in all its proceedings as if his name had been inserted in the complaint in the most formal manner, and he had answered it specifically. The agreement provided that the amendment might be made during the pendency of the' action, or on its conclusion, and in accordance with it the' *400 amendment to the complaint filed with the judgment roll may properly be read and treated as part of the pleadings. If the defendant Mahan had desired to file a formal answer to the allegations of the complaint, he should have insisted upon it at the time. He was probably satisfied with the answer of his codefendant on file, which put in issue the plaintiff’s title and set up all that he could have pleaded for himself. He had on the trial all the benefits of the most formal answer, and his connection with the case as a party sufficiently appears from the amendment filed.

2. The objection to the introduction of the articles of incorporation at the trial was that they were “ immaterial, irrelevant, and incompetent ” evidence. The specific objection now urged, that they were not sufficiently authenticated to be admitted in evidence, and that the certificates were made by .deputy officers, is one which the general objection does not include. Had it been taken at the trial and deemed tenable, it might have been obviated by other proof of the corporate existence of the plaintiff or by new certificates to the articles of incorporation. The rule is universal, that where an objection is so general as not to indicate the specific grounds upon which it is made, it is. unavailing on appeal, unless' it be of such a character that it could not have been obviated at the trial. The authorities' on this point are all one way. Objections to the admission of evidence must be of such a specific character as to indicate distinctly the grounds upon which the party relies, so as to give the other side full opportunity to obviate them at the time, if under any circumstances that can be done. United States v. McMasters, 4 Wall. 680; Burton v. Driggs, 20 Wall. 125; Wood v. Weimar, 104 U. S. 786, 795.

3. The objection Urged to the admission of evidence of acts done by the grantors of the plaintiff in locating and developing the Caledonia mine previous to February 28, 1877, is founded' upon the treaty between the United States and the Sioux Indians, concluded on the 29th of April, 1868, and ratified on the 16th of February, 1869. By the second article, a district' of country embracing the region known as the Black Hills of *401 Dakota, and which includes the mining property in controversy, was set apart as a reservation for the absolute and undisturbed use and occupation of those Indians, and such other friendly tribes or individual Indians to whose admission, from time to time, they and the United States might consent. - And. the United States' stipulated that no person, except those designated and authorized by the treaty, and such officers, agents, and employes of the government as might be authorized to enter upon Indian' reservations in the discharge of duties enjoined 'by law, should ever be permitted “to pass over, settle upon, or reside in the territory” described, or in such territory as might be added to the reservation. 15 Stat. 635.

In a subsequent agreement with the Indians, ratified by act of Congress on the 28th of February, 1877, the northern and western boundaries of the reservation were changed, leaving out the country of the Black Hills, which was relinquished by the Indians to the United States. That region was thus freed from the prohibition against -settlement upon it, and opened like other public lands of the United States to exploration and occupation under the mining laws. It is contended that the treaty operated as an actual prohibition against all acts taken by the predecessors of the plaintiff in the location and development of their mine, until the supplemental agreement of 1877, and that no support to their title can be derived from such acts, and, therefore, that no evidence of them was admissible.

Notwithstanding the prohibition of the treaty, as soon as it became known, early in 1874, that the precious metals existed in the Black Hills, large numbers of persons entered upon the reservation and proceeded to appropriate mining ground, and to work and develop the mines. The subject soon attracted the attention of the public authorities, and an exploring expedition, to ascertain and report as to the mining and agricultural resources of the country, was organized and sent out by the Secretary of the Interior in 1875. The report of the geologist accompanying the expedition, made in November of that year, confirmed the existence of the precious metals on the reservation, *402 In the meantime, as early as June, 1875, the Secretary, under direction of the President, appointed a commission to visit the Sioux nation, with a Anew to secure to the citizens of the United States the right to mine in the- country knovvn as the Black Hills. Report of Commissioner of Indian Affairs for 1875, pp. 184 and 185. The commission Avas unsuccessful, but the government was determined, notwithstanding, to open the mineral lands to development;' and by the act of August 15, 1876. 19 Stat. 176, making appropriations for the Indian service, it Avas provided that thereafter there should be no appropriation made for the subsistence of the Indians unless they should first agree to relinquish all right and claim to so much of their permanent reservation as lay west of the 103d meridian of longitude. This Avas the Black Hills country. Negotiations were resumed, and a supplementary agreement Avas concluded, Avhich was approved February 28, 1877, relinquishing that portion of the reservation, and ceding it to the United States. 19 Stat. 254.

While it is true that, before the new agreement, the prohibition against settlement upon the country constituting the reservation of the Indians remained in full force, yet it was evident to’ all that it would soon be Avithdrawn by' sonu arrangement; that immediately afterwards the mineral lands would be open to occupation and development; and that from that time mining claims taken up in the territory Avould be respected and protected. With the neAV agreement the results anticipated folloAved. The presence of the miners on the reservation up to that time was illegal, but from that time it Avas legal. ' Those then, in possession of mining claims, which had been taken up and developed in accordance with the rules of miners in mining districts of the country, Avere entitled to protection in their possessory claims as. against the intrusion of others. The effect of the Avithdrawal of the district from the reservation, and the consequent end of the prohibition, was to leave the predecessors of the plaintiff exempt from liability to be disturbed for their unlawful entry on the land, and free to take measures’ under the mining laws for the perfection of their; claims. Evidence of what had been done by them, the *403 location of their claim, its extent, the amount of work clone, in its development, was competent,, not as creating any absolute right to the property, but as showing the existence and condition of the property when their possession became lawful under the new agreement. ' Whether they should be protected in holding the property afterwards depended upon their future compliance with the laws, statutory and mining, governing the possession and use of mineral lands in Dakota. The rule laid down by the Supreme Covert of the territory is,, in our judgment, the correct one, which should govern cases of this kind, and that is substantially this : that where a party was in possession of a mining claim oh the 28th of February, 1877, with the requisite discovery, with the surface boundaries sufficiently marked, with the notice of location posted, and with a disclosed vein of ore, he could, by adopting what had been done, causing, a proper record to be made, and performing the amount of labor or making the improvements necessary to hold the claim, date his rights from that day; and that such location and labor and improvements would give him the right of possession.- By this rule substantial justice is done to all parties who were entitled to protection in their mining claims when the new agreement took effect.

Such proceedings were taken in this case by the owners of the Caledonia mine. They renewed their location and claim, making a record of their original 'claim and location and of the ■ supplementary one, in the proper mining records of the district.

The case appears to have been examined with great care in the Supreme Court of the territory, and every considerad tioh given to the positions of the appellants, and in its rulings we see no error.

Judgment affirmed.