delivered the opinion of the court.
On March 1, 1919, Joseph M. Hayes owned and was in the possession of 3,700 sheep in Morrow county, Oregon, where he resided, and where the sheep were duly assessed for taxation for the year 1919. In June following the sheep were shipped, consigned to the Chicago market. On June 19, the shipment reached Thompson Falls, Montana, and there the sheep were unloaded, and for the ensuing three months were grazed in Sanders county, as was permitted by the bill of lading. On July 8, the assessor of Sanders county listed the. sheep for assessment and taxation for 1919, and, the tax levy having been made and the tax extended, this property was charged with the sum of $518. Hayes applied to the county board of equalization for a cancellation of the assessment, but without avail, and his appeal to the state board was equally unsuccessful. Thereafter this suit was instituted to enjoin the treasurer from collecting the tax, and in the complaint the foregoing facts are set forth somewhat more in detail. The treasurer appeared by general demurrer, which was overruled, and, declining to plead further, suffered judgment to be rendered and entered in favor of( the plaintiff, and appealed to this court.
It is the contention of the plaintiff, concurred in by the district court, that the statute under which the revenue officers assumed to act is in contravention of the provisions of sections 1 and 11, Article XII, of the state Constitution, and for that reason null and void. At the earliest opportunity after our Constitution was adopted, an elaborate revenue measure was passed and approved (Laws 1891, p. 73), which provided generally for the assessment and taxation of all property subject to the jurisdiction of the state, and with minor amendments and modifications that Act has been carried forward and is now in full force and effect.
This legislation was the response to the constitutional mandate that the legislative assembly should pass all laws 'neces*312sary to carry into effect the provisions of Article XII of the Constitution, and particularly the provision in section 11 that all taxes shall be uniform upon the same class of subjects within the territorial limits of the authority levying the tax. It is elementary that the taxing power of the state does not extend beyond the territorial limits of the state, and neither does it extend to all subjects actually within the confines of the state, and upon which the state has the physical power to [1] impose a tax, as, for instance, property being transported in interstate commerce, while actually in transit through the state. (Bacon v. Illinois, 227 U. S. 504, 57 L. Ed. 615, 33 Sup. Ct. Rep. 299 [see, also, Rose’s U. S. Notes].)
Whatever may be said of its vast character and sweeping [2] extent, the power of taxation, of necessity, must be limited to subjects within the jurisdiction of the state, or, as otherwise characterized,' to subjects which have acquired a situs within the state for the purpose of taxation. In most jurisdictions the annual assessment of property subject to taxation is made as of some definite date, and the situs of the property determined as of that date. In pursuance of that general [3,4] policy, our legislature, by the repeated references in the revenue measure, evinced very clearly an intention that in. order for personal property, other than the net proceeds of mines, to acquire a situs for the purpose of taxation it must be within the state and subject to its jurisdiction at 12 o’clock noon on the first Monday of March. The references will be found in sections 2510, 2511, 2512, 2552, 2556, 2578, 2579, and 2601, Revised Codes, and possibly elsewhere, but the foregoing are sufficient for present purposes. No provision was made for the assessment of property introduced into the state after the first Monday of March, and in practice such property was not assessed for that fiscal year. Those principles have remained constant to the present time, unless modified by the legislation under which plaintiff’s property was assessed. The authority of the legislature thus to'fix a definite date as of which the situs of personal property for taxation is to be *313determined cannot be gainsaid, and since onr legislature did so, the question of uniformity of taxation is to be determined with reference to that fact.
On March 14, 1901, the Act in question was passed and approved which provided for the assessment and taxation of [5] livestock brought into this state for the purpose of grazing. (Laws 1901, p. 57.) Section 1 of that Act, now section 2531, Revised Codes, reads as follows: “All livestock brought into this state by any person or persons whomsoever, for the purpose of being grazed for any length of time whatsoever, shall be taxed for the year in which such livestock shall be brought into the state.” The other sections of the Act relate to the procedure, and are not directly involved here. Although the Act does not in express terms confine its operation to livestock brought into the state for grazing purposes after the first Monday of March, by necessary implication it does so, and such a construction is commanded, otherwise the entire Act would be meaningless. This is the only change, material to the determination of this appeal, which has been injected into the law since the enactment of the revenue statute in 1891. If this Act be upheld, it follows that since March 14, 1901, livestock brought into this state for grazing after the first Monday of March of any given year, immediately acquires a situs for the purpose of taxation for that year, whereas all other personal property brought into the state after that date does not, and is not subject to taxation for that year. In other words, plaintiff’s sheep are, by the terms of the Act, rendered subject to taxation in Montana for the year 1919, solely because of the fact that they were brought into the state to be grazed. If they had been introduced for any other purpose they would not have acquired a situs for taxation during the fiscal year 1919; or if personal property other than livestock, having the same value as plaintiff’s sheep, had been brought into the state after the first Monday of March, 1919, it would not have been subject to taxation for that year. It is because of this discrimination that plaintiff *314challenges the validity of section 2531 above, and insists that it provides for taxation, not uniform upon the same class of subjects.
The authority of the state to make a proper classification of property for the purpose of taxation is. settled beyond controversy in this jurisdiction. (Hilger v. Moore, 56 Mont. 146, 182 Pac. 477.) But a proper classification implies that there exist real differences as between the subjects constituting the different classes, and excludes the idea of arbitrary selection. (Northwestern Life Ins. Co. v. Wisconsin, 247 U. S. 132, 62 L. Ed. 1025, 38 Sup. Ct. Rep. 444.)
We are unable to perceive any distinction which can be drawn between a flock of 3,700 head of sheep of a particular breed, size, and description brought into this state after the first Monday of March for the purpose of grazing for any period, and a flock of the same size, breed, description and value .brought into the state at the same time for the purpose of being fed in pens for the same length of time, and yet this statute assumes to render the first flock subject to taxation, whereas the other is not. In other words, the attempted classification appears to be entirely arbitrary, and the unjust discrimination apparent.
This subject is not a new one. Migratory stock laws have been enacted in many of the western states, and have received consideration from the highest courts. As early as 1884 a statute very similar in its provisions .to the one now under review was before the supreme court of Kansas, and it was held to constitute a distinct departure from the rule of uniformity in the matter of taxation, and therefore unconstitutional and void. (Graham v. Commissioners of Chautauqua County, 31 Kan. 473, 2 Pac. 549.) Under like circumstances the same result was reached by the supreme court of Colorado in Board of County Commissioners v. Wilson, 15 Colo. 90, 24 Pac. 563.
Attention is directed to the decision in Wright v. Stinson, 16 Wash. 368, 47 Pac. 761, and Kelley v. Rhoads, 7 Wyo. *315237, 75 Am. St. Rep. 904, 39 L. R. A. 594, 51 Pac. 593, wherein a contrary conclusion was reached; but there is not any conflict in the decisions at all. While it is true that the migratory stock law of Washington, and the like character of statute in Wyoming, provided for the assessment and taxation of livestock brought into the' state for grazing after the date to which the general assessment of property related, the statute in each state also provided for the assessment and taxation of other personal property brought into the state after that date, so that there was not any discrimination against livestock brought into the state for grazing purposes, as was the case under the Colorado and Kansas statutes, and is the case under our section 2531 above.
Doubtless the state may designate one date as to which the [6] assessment of property belonging to one class shall relate, and a different date as to which the assessment of property belonging to a different class shall relate, but it may not discriminate against particular property belonging to any class; and if this state assumes to provide for the assessment of any property brought within its jurisdiction after the first Monday of March at 12 o’clock noon, it must also provide for the assessment of all other property of the same class so brought in. "
There is nothing to be found in the decision of Nelson Lumber Co. v. Loraine (C. C.), 22 Fed. 54, which militates against the views here expressed. The Wisconsin statute under review in that case provided for the like assessment and equal taxation of all property belonging to a particular class (logs, timber and ties). The only distinction made was in the time to which the assessment related—the property of nonresidents being assessed during the month of April, and the like character of property of residents assessed as of the 1st day of May. It was held that the local conditions justified .the distinction, and that the statute did not discriminate against the nonresident.
*316Our conclusion is that section 2531 above violates the rule of uniformity declared by our state Constitution, and that the assessment of plaintiff’s property in Sanders county for the fiscal year 1919 was without authority of law and void.
The judgment is affirmed.
Í'Affirmed.
Mr. Chief Justice Brantly and Associate Justices Hurly, Matthews and Cooper concur.