Argument for Plaintiff in Error. and municipal corporations on account of the lien of the United States upon the same for the costs of surveying, selecting and conveying the same, or because no patent has been issued therefor, but this provision shall not apply to lands unsurveyed: Provided, That any such land sold for taxes shall be taken by the purchaser, subject to the lien for costs of surveying, selecting and conveying, to be paid in such manner by the purchaser as the Secretary of the Interior may by rule provide, and to all liens of the United States, all mortgages of the United States, and all rights of the United States in respect of such lands: Provided, further, that this act shall apply only to lands situated opposite to and coterminous with completed portions of said roads and in organized counties: Provided, further, that at any sale of lands under the provisions of this act the United States may become a preferred purchaser, and in such case the lands sold shall be restored to the public domain and disposed of as provided by the laws relating thereto." Act of July 10, 1886, § 1, c. 764, 24 Stat. 143. The opinion of the court below devotes some space to an attempt to show that this act of Congress was accepted by the State of Nevada, or that the act of Congress, together with the state law, formed a sort of composite tax law under which these lands could be taxed and sold. It is not a question of acceptance or non-acceptance. It is a question whether the State has power to tax what it has taxed. In the series of decisions on the validity of state laws taxing shares in national banks this court has definitely settled the rule as to what is required to make valid state tax laws taxing property subject to taxation only by act of Congress. Bank of Commerce v. New York, 2 Black, 620; Bank Tax case, 2 Wall. 200; Van Allen v. Assessors, 3 Wall. 573; People v. Weaver, 100 U. S. 539. In these cases we see how emphatic has been the view of this court that the state law itself must contain the affirmative provisions which shall make it conformable to the act of Congress, and that the act of Congress cannot be relied upon to modify the state law or to coördinate itself with the state law. Opinion of the Court. That this state tax law does not tax these lands and that the state authorities have not taxed them in pursuance of the act of Congress seems clear. III. No lands granted to the Central Pacific Railroad Company can be taxed by a State prior to the issue of a patent. The grant to the Central Pacific Railroad excludes or reserves mineral lands—not merely the minerals, but mineral lands. The right and power to ascertain which of the lands, included within the territorial limits of the grant as fixed by the definite location of the line of the road, are mineral and which non-mineral is vested exclusively in the United States administrative officers, and is conclusively proved only by the issue of a patent. Argument on this proposition seems unnecessary after the decision of this court in Barden v. Northern Pacific Railroad, 154 U. S. 288. In the case at bar the grant of the unpatented lands is, and remains, a float until a patent issues; for, until then, no one can say whether any particular acre of land passes or not. Mr. John C. Chaney for defendant in error. Mr. Robert M. Beatty, attorney general of the State of Nevada, and Mr. Henry Mayenbaum filed a brief for defendant in error. MR. JUSTICE BROWN, after stating the case, delivered the opinion of the court. There appear to be within the county of Lander four classes of lands embraced within the Pacific land grants of 1862 and 1864. (1.) Patented lands to the amount of 24,123 acres, assessed at $1.25 per acre, concerning the taxability of which there is no dispute. Railway Co. v. McShane, 22 Wall. 444. (2.) Unsurveyed lands to the amount of 195,200 acres, assessed at 50 cents per acre, and held, both by the district court and by the Supreme Court of the State, not to be sub Opinion of the Court. ject to taxation. See also act of July 10, 1886, c. 764, § 1, 24 Stat. 143. No question is made with regard to the propriety of this ruling. (3.) Surveyed but unpatented lands, upon which the costs of survey have been paid; 8562 acres. These would, of course, be subject to taxation if the following class was adjudged to be so subject. (4.) Surveyed but unpatented lands, upon which the costs of survey have not been paid; 122,824 acres. 1. The principal dispute is with regard to the fourth class, that is, unpatented lands which have been surveyed, but the costs of which survey have not been paid. As to lands of this class it was held by this court in Railway Co. v. Prescott, 16 Wall. 603, that, although lands sold by the United States may be taxed before the government has parted with the legal title by issuing the patent, this principle was to be understood as applicable only to cases where the right to the patent is complete, and the equitable title fully vested, without anything more to be paid, or any act done going to the foundation of the right; and hence, where there had been a large grant to a railroad company, if prepayment by the grantee of the cost of surveying the lands granted be required by the statute making the grant, before any of the lands shall be conveyed, no title vested in the grantee, and the State could not levy taxes on the land, and under such levy sell and make a title which might defeat the lien of the United States. In this particular, this case was affirmed in Railway Co. v. McShane, 22 Wall. 444, 462, and Northern Pacific Railroad v. Traill County, 115 U. S. 600. Apparently to provide for this contingency and to render these lands subject to state taxation, Congress, on July 10, 1886, 24 Stat. 143, passed an act to provide for the taxation of railroad grant lands and for other purposes, the first section of which enacted "that no lands granted to any railroad corporation by any act of Congress shall be exempted from taxation by States, Territories and municipal corporations on account of the lien of the United States upon the same for the costs of surveying, selecting and conveying the same, or be Opinion of the Court. cause no patent has been issued therefor; but this provision shall not apply to lands unsurveyed: Provided, That any such land sold for taxes shall be taken by the purchaser subject to the lien for costs of surveying, selecting and conveying, to be paid in such manner by the purchaser as the Secretary of the Interior may by rule provide and to all liens of the United States, all mortgages of the United States, and all rights of the United States in respect to such lands: Provided further, That this act shall apply only to lands situated opposite to and coterminous with completed portions of said roads, and in organized counties: Provided further, That at any sale of lands under the provisions of this act the United States may become a preferred purchaser, and in such case the lands sold shall be restored to the public domain and disposed of as provided by the laws relating thereto." In view of this statute it is difficult to see how these lands, which are the very ones provided for by the statute, can escape taxation, if the State chooses to tax them. The argument of the railroad company in this connection is that, by the General Statutes of Nevada upon the subject of taxation, § 1080,"nothing shall be so construed as to exempt from taxation possessory claims to the public lands of the United States, or of this State: .. and provided further, that nothing herein shall be so construed as to interfere with the primary title to the lands belonging to the United States; that by § 1081, "the term 'real estate,' when used in this act, shall be deemed and taken to mean and include the ownership of, or claim to, or possession of, or right of possession to any lands within the State, and the claim by or the possession of any person, firm, corporation, association or company to any land, and the same shall be listed under the head of real estate;" that, by § 1088, "it is the duty of the assessor to prepare a tax list, or assessment roll, shall be listed in which . . all real estate, including the ownership or claim to, or possession of, or right of possession to any land and improvements," etc.; that this action was brought by the State of Nevada to subject these lands to taxation upon the ground that the railroad company Opinion of the Court. had a "possessory claim " to them, which the proper officers of the State had assessed for taxes; that the railroad company, in its answer, denied that it had any possessory claim in or to said lands, and alleged that its only interest was that derived from the land grant acts of Congress of 1862 and 1864, and that as to said lands a portion were unsurveyed and unpatented, a portion surveyed but unpatented and costs of survey unpaid, and but a small portion patented; that the pleadings thus presented a direct issue as to whether the company had a "possessory claim" in these lands, which could be taxed by the State; that the only evidence upon such issue was the stipulation above recited, to the effect that the defendant never had any other possession of any part of said lands than such as may be inferred from executing said mortgages and leases, and by virtue of the land grants; that the Supreme Court of the State, in considering the taxing statute above recited, held, in respect to the unsurveyed lands, that the terms "possessory claims," "claim to possession or right to possession" to any lands did not mean such right or claim when not accompanied by actual possession, and hence that unsurveyed lands were not subject to taxation; that such construction of the term "possessory claims" applies to surveyed as well as unsurveyed lands; and hence it must follow that there is nothing to tax, unless the title is subject to taxation, and that this court has held in the three cases above cited, that the title to surveyed patented lands, upon which the costs of survey have not been paid, is not subject to taxation. It is a sufficient answer to this argument to say that, whether the inclusion of these lands in the land grant acts of 1862 and 1864, and the subsequent mortgaging and leasing of them by the railroad company, constituted a "possessory claim" to the lands under the taxing laws of Nevada, is not a Federal question, but a question as to the proper construction of the words 66 possessory claim," used in the state statute. It is true that, with respect to the unsurveyed lands, the Supreme Court held that the railroad company had no such actual and substantial possession as would justify their taxation under the statute, and that it does not expressly appear from the opinion that |