delivered the opinion of the Court:

The allotments held by My Soul Tiebault at the time of his decease are not here questioned in any way. The sole question, therefore, with which we are confronted, is whether, under .the facts above set forth, the Secretary of the Interior has jurisdiction to readjudicate the question as to who are the legal heirs of said Tiebault. Under the act of 1887 (24 Stat. at L. 388, chap. 119, Comp. Stat. 1913, sec. 4195), from which we have quoted, the heirs of a deceased allottee, “according to the laws of the State or Territory” where the land was located, succeeded to his rights, and the act of June 25, 1910 (36 Stat. at L. 855, chap. 431, Comp. Stat. 1913, sec. 4226), clothed the Secretary with exclusive jurisdiction to ascertain “the legal heirs of such decedent.” His decision upon this question, the act specifically' declares, “is final and conclusive.” Rut that does not mean that he could arbitrarily ignore the legal heirs of a deceased allottee,' and decide in favor of a collateral heir or a stranger in blood. Such a decision would be arbitrary or capricious, and not sustainable under any view of this act. See United States ex rel. *419Ness v. Fisher, 223 U. S. 683, 691, 56 L. ed. 610, 612, 32 Sup. Ct. Rep. 356. We think, therefore, that this act merely clothed the Secretary with jurisdiction to identify the legal heirs of such decedent, and that in so doing he was as much bound by the laws of descent in the jurisdiction where the lands were located as would be any other tribunal.

The jurisdiction of the court in which the adoption proceedings were had is not questioned, nor is it denied that, if the decree rendered by that court is to stand, appellants are the legal heirs of My Soul Tiebault. The sole justification for the attempted reopening of the Departmental decision of January 11, 1913, according fo the answer to the bill, is that a collateral heir, seventeen years after this decree of adoption (declared by sec. 800 of the statutes of Nebraska for 1.895 to be “conclusive upon all persons interested in such proceedings or matter,” which proceeding's the sup reuní court of Nebraska, in Ferguson v. Herr, 64 Neb. 662, 90 N. W. 625, 94 N. W. 542, has held to be “judicial” in character), seeks to “show that the alleged decree of adoption was void on the ground that it was secured by fraud.” Appellants’ petition that the Secretary exercise the discretion which the statutes reposed in him, and issued to them fee simple patents to the Tiebault allotments, raised but one issue, namely, whether they were capable of managing their own affairs, and hence entitled to such patents. This petition did not, as contended by counsel for the Government, raise any issue as to their heirship. It is not contended that appellants were guilty of any fraud in procuring their adoption by Tiebault, nor could it well be, since they were infants at the time. This, therefore, is not an attempt by an alleged wrongdoer to profit by his own fraud. Phillips v. Chase, 203 Mass. 556, 30 L.R.A.(N.S.) 159, 89 N. E. 1049, 17 Ann. Cas. 544. Tiebault, by procuring the adoption decree, which was in substantial conformity with the provisions and requirements of the local statute, and for ten years thereafter recognizing its validity and receiving the benehts of the relationship thus created, was estopped to challenge it. Ferguson v. Herr, 64 Neb. 660, 90 N. W. 625, 94 N. W. 542. Nor is one claiming under him in any *420better position than he would have been if living. In Wolf's Appeal, 10 Sadler (Pa.) 139, 22 W. N. C. 93, 13 Atl. 760, the administrator and collateral heirs of an adoptive parent sought to have the decree of adoption set aside on the ground that certain false statements had induced it. The court of common pleas held that such administrator and heirs could not be heard to question a decree entered at the instance of the adoptive parent, through whom they claimed. The court said: “When the proceedings were instituted, and the decree of adoption made, the court undoubtedly had jurisdiction of the subject-matter, to wit, the child Caroline O. Sankey, and the promotion of her welfare. Immediately on the entry of the decree, and thereafter, she was entitled to be maintained and educated by Samuel Sankey, and on his death was entitled to inherit as his child. Nearly nine years after the decree was entered, and more than one year after the death of her adopted father, his administrator and collateral heirs come into court and ask that this decree of adoption be vacated. They are not here in the interest nor on behalf of the innocent subject of adoption, but decidedly against the same. They are either strangers to the adoption proceedings, and therefore have no standing in court, or they are privies in blood or in law, and' stand in the shoes of Samuel Sankey, through and under whom they claim.” An appeal was prosecuted to. the supreme court of the State, where the decision was affirmed “on the opinion of the learned judge of the court below.” See also Parsons v. Parsons, 101 Wis. 76, 70 Am. St. Rep. 894, 77 N. W. 147, and 1 R. C. L. 624. If a collateral heir would have no standing to challenge such a decree in a direct proceeding, surely he ought not to be permitted to question it indirectly. To permit him to do so would amount to an arbitrary exercise of power on the part of the Secretary, warranting the interposition of a court of equity.

•' But, apart from the question of the conclusiveness of the decree of adoption, we think the Secretary, under the facts stated, was without jurisdiction to reopen the decision of January 11, 1913. There is no averment or pretense that such decisión *421was procured by fraud. The attack is upon a decree of adoption regularly entered by a court of competent jurisdiction in the State of Nebraska. The statute under which the Secretary is acting in terms declares that the decision of the Department identifying the heirs of a deceased allottee shall be final and conclusive. No rule of the Department providing for a rehearing within a stated time, promulgated under the authority of the act of June 25, 1910, has been called to our attention. In United States ex rel. Knight v. Lane, 228 U. S. 6, 10, 57 L. ed. 709, 711, 33 Sup. Ct. Rep. 407, it was held that a decision of the Secretary of the Interior revoking his prior approval of an adjustment between contestants, one of whom was a minor’, and which was not arbitrary or capricious, but given after a hearing and in the exercise of the discretion confided to him by law, could not be reviewed by the courts. But there the application for rehearing was made within the thirty days within which such an application could be filed under the rules of the Department, and there was no provision of the statute that the original decision when rendered should be final and conclusive. Here the Department regularly having determined the identity of the legal heirs of the deceased allottee, its decision was final, and no more subject to review than would have been a similar decision of a judicial tribunal. United States v. Stone, 2 Wall. 525, 17 L. ed. 765; Noble v. Union River Logging R. Co. 147 U. S. 165, 37 L. ed. 123, 13 Sup. Ct. Rep. 271; Lane v. Watts, 234 U. S. 525, 540, 58 L. ed. 1440, 1456, 34 Sup. Ct. Rep. 965.

Since the Secretary, under the facts stated, exceeded his powers in attempting to readjudicate the question as to who are the legal heirs of My Soul Tiebault, it follows that serious, if not irreparable, injury to appellants will result. As his legal heirs, they are the equitable owners of the allotments of which he died seised, and a readjudication of the question of their heirship will not only involve them in unnecessary trouble and expense, but cast a cloud upon their title. The order will be reversed, with costs, and the cause remanded for an order direct*422fng the Secretary to recognize and enforce the Departmental decision of January 11, 1913. Reversed.

A writ of error to the Supreme Court of the United States was allowed April 24, 1915'.