Mr. JUSTICE MARSHALL delivered the opinion of the Court.In this case, we are called upon to review the judgment of the District Court for the Southern District of Mississippi that the State of Mississippi may require out-of-state liquor distillers and suppliers to collect and remit to the State a wholesale markup on liquor sold to officers' clubs, ship's stores, and post exchanges located on various military bases over which the United States exercises either exclusive jurisdiction or jurisdiction concurrent with the State.Prior to 1966, the State of Mississippi prohibited the sale or possession of alcoholic beverages within its borders.  In that year, Mississippi passed a local option alcoholic beverage control law subject to the requirement that the State Tax Commission be the sole importer and wholesaler of alcoholic beverages distributed within the State. [Footnote 1]  The Tax Commission was given exclusive authority to act as wholesale distributor in the sale of alcoholic beverages to licensed retailers within the State"including, at the discretion of the Commission, any retail distributors operating within any military post . . . within the boundaries of the State, . . . exercising such control over the distribution of alcoholic beverages as [seems] right and proper in keeping with the provisions and purposes of this act. [Footnote 2]"In conjunction with these transactions with retailers, the Commission was directed to Page 412 U. S. 365"add to the cost of all alcoholic beverages such . . . markups as in its discretion will be adequate to cover the cost of operation of the State wholesale liquor business, yield a reasonable profit, and be competitive with liquor prices in neighboring states. [Footnote 3]"Under the authority granted to it by the Act, the Tax Commission promulgated Regulation 25, [Footnote 4] which gives military post exchanges, ship's stores, and officers' clubs the option of purchasing liquor either from the Commission or directly from the distiller.  However, insofar as purchases are made directly from the distillers by such military facilities, the regulation requires the distiller to collect and remit to the Tax Commission the latter's "usual wholesale markup."  During the period involved in this case, the Tax Commission's wholesale markup was 17% on distilled spirits and 20% on wine.Four United States military bases are located in the State of Mississippi -- Keesler Air Force Base, the Naval Construction Battalion Center, Columbus Air Force Base, and Meridian Naval Air Station.  Prior to 1966, the officers' clubs, the post exchanges, and the ship's stores --  Page 412 U. S. 366 which are run with funds derived from operations, rather than from funds appropriated by the United States -- on these four bases had purchased liquor from distillers and suppliers located outside the State of Mississippi.  Following the passage of the Mississippi local option law, these nonappropriated fund activities elected to continue the practice of purchasing liquor supplies outside the State, rather than to purchase liquor from the Commission.  Efforts were made by military authorities to convince the Commission not to collect the markup on out-of-state liquor purchases by nonappropriated fund activities, but these efforts failed, and the Commission compelled out-of-state distillers and suppliers to collect and remit the markup on military sales under threat of criminal prosecution and of delisting, that is, withdrawal of the privilege of selling to the Commission for retailing within Mississippi. [Footnote 5]  The military authorities sought to pay the markup into an escrow fund pending judicial determination of the legality of the markup as applied to military purchases.  But the Commission refused to accept such an arrangement, and, in order to obtain liquor supplies, the nonappropriated fund activities have had to pay the markup to the distillers and suppliers, albeit under protest. [Footnote 6]In November, 1969, the United States brought this action seeking declaratory and injunctive relief against the continued enforcement of Regulation 25, plus a judgment in the total amount paid to the Commission, through the suppliers, since the imposition of the markup on military purchases.  The complaint alleged that the United States has exclusive jurisdiction over Keesler Air Force Base and the Naval Construction Battalion Center, and that Mississippi and the United States exercise concurrent Page 412 U. S. 367 jurisdiction over Columbus Air Force Base and Meridian Naval Air Station.  The complaint contended that the Regulation was invalid because it constituted an attempt by the State to legislate with respect to military facilities and territory over which the Congress has exclusive legislative authority; [Footnote 7] to impose a tax on federal instrumentalities, and thereby infringe upon the Federal Government's immunity from state taxation; [Footnote 8] and to interfere with federal procurement regulations and policy established by the Secretary of Defense pursuant to authority granted to him by Congress. [Footnote 9]  The complaint also asked that a three-judge court be convened.On cross-motions for summary judgment, the District Court ruled in favor of the Commission, upholding the validity of the challenged Regulation.  340 F. Supp. 903 (SD Miss.1972).  The District Court agreed that the United States had exclusive jurisdiction over two of the four bases and concurrent jurisdiction over the remaining two.  But it concluded that Congress' constitutional powers over the military forces and over territory belonging to the United States"are diminished by the express prohibition of the XXI Amendment as to all packaged liquor transactions which (1) are made on exclusively federal enclaves but without restriction upon use and consumption of such liquors outside the base, or (2) take place on military installations over which the state and federal government exercise concurrent jurisdiction."Id. at 904.  In light of this conclusion, the District Court found it unnecessary to consider the import of the procurement regulations issued by the Secretary of Defense.  Nor did it discuss the contention that the markup constituted Page 412 U. S. 368 an impermissible tax upon federal instrumentalities.  On appeal by the United States, we noted probable jurisdiction, 409 U.S. 1005 (1972). [Footnote 10]  For the reasons which follow, we now hold that the District Court erred in concluding that the Twenty-first Amendment provides the State with sufficient authority over liquor transactions to support the application of the Regulation to the two bases over which the United States exercises exclusive jurisdiction, [Footnote 11] and we vacate and remand the case to the District Court for consideration of further arguments, relevant to the nonappropriated fund activities on all four bases, that it did not reach. Page 412 U. S. 369IA. With respect to the two bases over which it claims exclusive jurisdiction, Keesler Air Force Base and the Naval Construction Battalion Center, the Government places principal reliance upon Art. I, § 8, cl. 17, of the Constitution.  That clause empowers Congress to"exercise exclusive Legislation . . . over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings."In Pacific Coast Dairy, Inc. v. Dept. of Agriculture, 318 U. S. 285 (1943), the Court considered that clause sufficient to render ineffective an attempt by the State of California to fix the prices at which California milk producers could sell milk to military authorities at Moffett Field, over which the United States exercised exclusive jurisdiction."When the federal government acquired the tract [upon which Moffett Field was located], local law not inconsistent with federal policy remained in force until altered by national legislation.  The state statute involved was adopted long after the transfer of sovereignty, and was without force in the enclave.  It follows that contracts to sell and sales consummated within the enclave cannot be regulated by the California law.  To hold otherwise would be to affirm that California may ignore the Constitutional provision that 'This Constitution, and the laws of the United States which shall be made in Pursuance thereof . . . shall be the supreme Law of the Land; . . .'  It would be a denial of the federal power 'to exercise exclusive Legislation.'  As respects such federal territory Congress has the combined Page 412 U. S. 370 powers of a general and a state government."Id. at  318 U. S. 294 (footnotes omitted).The view of Art. I, § 8, cl. 17, expressed in Pacific Coast Dairy was reaffirmed in Paul v. United States, 371 U. S. 245,  371 U. S. 263-270 (1963).  There, the Court was confronted with another attempt by California to enforce minimum wholesale price regulations on sales of milk to the United States at three other military installations located within the State.  A portion of the milk was purchased -- as are the liquor supplies here at issue -- with nonappropriated funds for use at officers' clubs and for resale at post exchanges.  As to these nonappropriated fund purchases, the Court found it necessary to remand the case to determine whether the state regulatory scheme predated the transfer of sovereignty over any of the particular bases to the United States, [Footnote 12] and, even if not, whether the United States, in fact, exercised exclusive jurisdiction over the areas in which purchases and sales of milk were made.  But, in so doing, the Court emphasized that"[t]he cases make clear that the grant of 'exclusive' legislative power to Congress over enclaves that meet the requirements of Art. I, § 8, cl. 17, by its own weight, bars state regulation without specific congressional action."Id. at  371 U. S. 263.Were it not for the fact that we deal here with a State's Page 412 U. S. 371 attempt to regulate and derive income from wholesale transactions in liquor -- a fact which raises further questions as to the extent of the power conferred upon the States under the Twenty-first Amendment and the possibility of consent by the United States to state taxation -- Pacific Coast Dairy and Paul would seem to be sufficient to dispose of this case insofar as Keesler Air Force Base and the Naval Construction Battalion Center are concerned.  See also James v. Dravo Contracting Co., 302 U. S. 134,  302 U. S. 140 (1937); Standard Oil Co. v. California, 291 U. S. 242 (1934).  The transactions here at issue are strictly between the United States and out-of-state distillers and suppliers.  The goods are ordered by the officers' clubs and other nonappropriated fund activities, and then delivered within the military bases over which the United States claims exclusive jurisdiction.  Thus, with respect to the initial sale and delivery of the liquor by the suppliers to military facilities located in exclusively federal enclaves, nothing occurs within the State that gives it jurisdiction to regulate the initial wholesale transaction. [Footnote 13]  Cf. Polar Ice Cream & Creamery Co. v. Andrews, 375 U. S. 361,  375 U. S. 382-383 (1964); Penn Dairies, Inc. v. Milk Control Comm'n, 318 U. S. 261 (1943).There can be no question that the tracts of land upon which Keesler Air Force Base and the Naval Construction Battalion Center are located were "purchased by the Consent of the Legislature" of Mississippi within the meaning of Art. I, § 8, cl. 17.  Despite its ultimate resolution of the case, the District Court acknowledged that the United States had acquired exclusive jurisdiction over these two bases.  340 F. Supp.  at 904, 906.  The Federal Government acquired the relevant lands by condemnation Page 412 U. S. 372 between 1941 and 1950. [Footnote 14]  And, throughout the period of acquisition, the State had expressly given its"consent . . in accordance with the 17th clause, 8th section, and of the 1st article of the Constitution of the United States, to the acquisition by the United States, by purchase, condemnation or otherwise, of any land in this state . . . for custom houses, post offices, or other public buildings, [Footnote 15]"subject only to the right of the State to serve civil and criminal process upon such public lands. [Footnote 16]  True, the assent of the United States to the exercise of exclusive jurisdiction over the lands occupied by the two bases was a necessary final step in light of 40 U.S.C. § 255, [Footnote 17] but such assent was given through a Page 412 U. S. 373 series of letters from Government officials to the Governors of Mississippi between 1942 and 1950. [Footnote 18]Accordingly, unless the fact that in this case the State has attempted to derive revenue from private wholesale liquor transactions provides a decisive distinction, our prior cases make it clear that the Tax Commission could not attach its markup to the sale and delivery of liquor by out-of-state suppliers to nonappropriated fund activities within Keesler Air Force Base and the Naval Construction Battalion Center.B. But the Tax Commission contends -- as the District Court held -- that the application of the markup regulation to the two bases over which the United States exercises exclusive jurisdiction is sustainable on the basis of the broad regulatory authority conferred upon the States by the Twenty-first Amendment.  The second section of the Twenty-first Amendment provides:"The transportation or importation into any State, Territory, or possession of the United States for delivery or use therein of intoxicating liquors, in violation of the laws thereof, is hereby prohibited."In Collins v. Yosemite Park & Curry Co., 304 U. S. 518 (1938), a concessionaire which operated hotels, camps, Page 412 U. S. 374 and stores in Yosemite National Park, under a contract with the Secretary of the Interior, sought to enjoin the efforts of California authorities to enforce the State's Alcoholic Beverage Control Act within the limits of the Park.  The state liquor law would have required the concessionaire to apply for permits for the importation and sale of liquor and to pay related taxes and fees.  The Court found that the State had ceded to the United States, and that the United States had accepted, exclusive jurisdiction over Yosemite National Park, except insofar as the State had expressly reserved the right to tax persons and corporations within the Park.  Id. at  304 U. S. 527-530.  In light of this determination, the Court held that "[a]s there is no reservation of the right to control the sale or use of alcoholic beverages, such regulatory provisions as are found in the Act" -- namely, the provisions concerning importation and sales permits -- "are unenforceable in the Park."  Id. at  304 U. S. 530.  In support of its attempt to apply the permit provisions within the Park, the State placed specific reliance upon the regulatory authority conferred upon it by § 2 of the Twenty-first Amendment.  But the Court rejected this argument, agreeing instead with the District Court's conclusion"that, though the Amendment may have increased 'the state's power to deal with the problem . . . [of liquor importation], it did not increase its jurisdiction.'"Id. at  304 U. S. 538.  The Court then went on to state:"As territorial jurisdiction over the Park was in the United States, the State could not legislate for the area merely on account of the XXI Amendment.  There was no transportation into California 'for delivery or use therein.'  The delivery and use is in the Park, and under a distinct sovereignty.  Where exclusive jurisdiction is in the United States, without power in the State to regulate alcoholic beverages, Page 412 U. S. 375 the XXI Amendment is not applicable."Ibid.  (Footnotes omitted.)  It is true, as the Tax Commission argues, that the Court did sustain the application of the tax provisions of the state liquor law within the Park.  But this aspect of the decision was bottomed specifically on the State's reservation of taxing authority in its cession of lands to the United States, id. at  304 U. S. 532,  304 U. S. 536.Collins would seem to compel the conclusion that, absent an appropriate express reservation -- which is lacking here -- the Twenty-first Amendment confers no power on a State to regulate -- whether by licensing, taxation, or otherwise -- the importation of distilled spirits into territory over which the United States exercises exclusive jurisdiction.  See also Johnson v. Yellow Cab Transit Co., 321 U. S. 383 (1944).  Certainly, the Amendment was intended to free the State of"traditional Commerce Clause limitations when it restricts the importation of intoxicants destined for use, distribution, or consumption within its borders."Hostetter v. Idlewild Bon Voyage Liquor Corp., 377 U. S. 324,  377 U. S. 330 (1964).  See also Joseph E. Seagram & Sons, Inc. v. Hostetter, 384 U. S. 35,  384 U. S. 42 (1966).  But the Government contends that here, as in Collins, there was no "transportation or importation [of liquor] into [the] State . . . for delivery or use therein" within the meaning of the second section, and therefore the Twenty-first Amendment does not assist the Tax Commission's case.  We agree.The District Court acknowledged that Keesler Air Force Base and the Naval Construction Battalion Center"are to Mississippi as the territory of one of her sister states or a foreign land.  They constitute federal islands which no longer constitute any part of Mississippi nor function under its control."340 F. Supp.  at 906.  And it recognized that, in light of Collins,"[t]he importation Page 412 U. S. 376 of property onto these bases for use thereon would clearly be outside the ambit of the XXI Amendment."Id. at 906-907.  But the court considered Collins to be limited strictly to the situation in which delivery and use of the liquor was restricted to the exclusive enclave, whereas, in this case,"[t]he undisputed facts show that it was acquired for the purpose of being sold to individuals for their use and consumption either on the base or in the surrounding state."Id. at 907.  Such off-base consumption was sufficient, in the District Court's view, to subject the transactions between the out-of-state suppliers and the nonappropriated fund activities to the regulatory authority granted to Mississippi under the Twenty-first Amendment.  We think, however, that the District Court unjustifiably narrowed the decision in Collins.There is, in fact, no indication in Collins that the liquor purchased from the concessionaire's facilities in the Park was always consumed within the limits of the Park.  To the contrary, the complaint in that case specifically stated that the liquor imported for sale in the park facilities was sold "for consumption on or off the premises where sold." [Footnote 19]  Hence, it is just as reasonable to assume that some of the liquor sold in the Park was consumed outside its limits in the State of California as it is to assume that some of the liquor sold on these two bases was ultimately consumed in the State of Mississippi. [Footnote 20]  The Page 412 U. S. 377 Collins Court, in rejecting California's reliance upon the Twenty-first Amendment, pointed, to be sure, to the fact that "delivery and use" of the liquor was "in he Park," 304 U.S. at  304 U. S. 538.  But, considered in the context of the case, the Court's reference clearly was to the transaction between the out-of-state suppliers and the park concessionaire.  It was that transaction which California sought to regulate, and, insofar as that transaction was concerned, the delivery and use -- that is, the delivery, storage, and sale -- of the liquor occurred exclusively within the Park.  The particular transactions at issue in this case between out-of-state suppliers and the military facilities stand on no different footing, and thus, given that the State has retained only the right to serve process on the two bases, Collins is dispositive of the Commission's effort to invoke the State's authority under the second section of the Twenty-first Amendment to impose its markup on these transactions.This is not to suggest that the State is without authority either to regulate liquor shipments destined for the bases while such shipments are passing through Mississippi or to regulate the transportation of liquor off the bases and into Mississippi for consumption there.  Thus, while it may be true that the mere"shipment [of liquor] through a state is not transportation or importation into the state within the meaning of the [Twenty-first] Amendment,""Carter v. Virginia, 321 U. S. 131,  321 U. S. 137 (1944), a State may, in the absence of conflicting federal regulation, properly exercise its police powers to regulate and control such shipments during their passage through its territory insofar as necessary to prevent the 'unlawful diversion' of liquor 'into the internal commerce of the State,"see Hostetter v. Idlewild Bon Voyage Liquor Page 412 U. S. 378 Corp., 377 U.S. at  377 U. S. 333,  371 U. S. 331 n. 10; Carter v. Virginia, supra; Duckworth v. Arkansas, 314 U. S. 390 (1941).  And the State, of course, remaining free to regulate or restrict, under § 2 of the Twenty-first Amendment, the transportation off the two bases of liquor that has been purchased and is, in fact, "destined for use, distribution, or consumption within its borders, see Joseph E. Seagram & Sons, Inc. v. Hostetter, 384 U.S. at  384 U. S. 42; see also California v. LaRue, 409 U. S. 109,  409 U. S. 114 (1972).But there is no indication here that the markup is an effort to deal with problems of diversion of liquor from out-of-state shipments destined for one of the two bases.  Nor need we now decide the precise parameters of the State's authority to regulate efforts to import liquor from the exclusively federal enclaves, since that question is not before us.  For our purposes here, it suffices to note that any legitimate state interest in regulating the importation into Mississippi of liquor purchased on the bases by individuals cannot effect an extension of the State's territorial jurisdiction so as to permit it to regulate the distinct transactions between the suppliers and the nonappropriated fund activities that involve only the importation of liquor into the federal enclaves which "are to Mississippi as the territory of one of her sister states or a foreign land," 340 F. Supp.  at 906.  To conclude otherwise would be to give an unintended scope to a provision designed only to augment the powers of the States to regulate the importation of liquor destined for use, distribution, or consumption in its own territory, not to "increase its jurisdiction,'" Collins v. Yosemite Park & Curry Co., 304 U.S. at  304 U. S. 538.C. Before this Court, the Tax Commission also asserts that the markup might properly be viewed as a sales tax and that the United States has consented to the imposition of such a "tax" in the context of the two exclusive jurisdiction bases under the Buck Act of 1940, Page 412 U. S. 379 54 Stat. 1059, now 4 U.S.C. §§ 105-110.  Section 105(a) of that Act provides in part:"No person shall be relieved from liability for payment of, collection of, or accounting for any sales or use tax levied by any State, or by any duly constituted taxing authority therein, having jurisdiction to levy such a tax, on the ground that the sale or use, with respect to which such tax is levied, occurred in whole or in part within a Federal Area. . . ."4 U.S.C.§ 105(a).  However, § 107(a) of the Act spells out certain exceptions to the consent provision contained in § 105(a).  Specifically, § 107(a) states that § 105(a) "shall not be deemed to authorize the levy or collection of any tax on or from the United States or any instrumentality thereof. . . ."  Whether the markup should be treated as a tax on sales occurring within a federal area within the meaning of § 105(a), see also 4 U.S.C. § 110(b), and, if so, whether the exception contained in § 107(a) nevertheless serves to remove the markup from the consent provision for purposes of the two exclusively federal enclaves are issues which the record reveals were never considered, much less decided, by the District Court.  Having found that the District Court erred in the basis on which it did dispose of this case, we think that these additional issues are appropriately left for determination by that court in the first instance on remand.IIThe two bases over which the United States claims to exercise jurisdiction concurrent with the State Columbus Air Force Base and Meridian Naval Air Station -- present somewhat different problems.  Since the United States has not acquired exclusive jurisdiction over the land upon which these bases are located, the Government Page 412 U. S. 380 is unable to rest its claims for immunity from the markup with respect to purchases of liquor for the nonappropriated fund activities of these bases on Art. I, § 8, cl. 17.  Rather, it bases its argument on the theories that the markup either is an unconstitutional tax upon instrumentalities of the United States [Footnote 21] or is invalid under the Supremacy Clause because it conflicts with federal procurement regulations and policy. [Footnote 22]  The District Court specifically found it unnecessary to reach the Government's argument under the Supremacy Clause, and implicitly declined to reach the Government's argument concerning taxation of United States instrumentalities.  Instead, having concluded that, despite Art. I, § 8, cl. 17, the Twenty-first Amendment permitted the Tax Commission to apply the markup to out-of-state purchases destined for nonappropriated fund activities on the two bases over which the United States exercises exclusive jurisdiction, the District Court simply reasoned that,"[a] fortiori, the liquor sales made on the two bases over which the federal and state governments exercise concurrent jurisdiction -- Meridian and Columbus -- are similarly subject to Mississippi law."340 F. Supp.  at 907.The District Court's rationale for adopting this view is not entirely clear.  Certainly it was correct when it further observed that"as to the concurrent jurisdiction bases, the liquor sales transactions occurred within the jurisdiction of the State of Mississippi, even where the consumption or other use of the liquor was consummated within the territorial confines of the base."Ibid.  But this serves only to dispose of any question under Art. I, § 8, cl. 17.  As already noted, however, the Government does not purport to rest its case with respect to transactions Page 412 U. S. 381 involving the two bases over which it exercises only concurrent jurisdiction upon that clause.  In any event, we have now concluded that the District Court erred in ruling that the Twenty-first Amendment empowered the State Tax Commission to apply the markup to transactions between out-of-state distillers and nonappropriated fund activities located on the two exclusively federal enclaves.  Our conclusion eliminates the essential premise of the District Court's decision concerning the two concurrent jurisdiction bases.  While the arguments upon which the Government does rely with respect to the purchase of liquor destined for those two bases present, to be sure, only questions of law which we might now decide, we believe it would be useful to have the views of the District Court on these additional arguments, and we therefore remand the case to the District Court to allow it to consider initially the Government's instrumentality and Supremacy Clause arguments.  Cf. Lewis v. Martin, 397 U. S. 552,  397 U. S. 560 (1970); FCC v. WJR, 337 U. S. 265,  337 U. S. 285 (1949).The judgment of the District Court is vacated and the case is remanded for further proceedings consistent with this opinion.It is so ordered
U.S. Supreme CourtUnited States v. State Tax Commission of Mississippi, 412 U.S. 363 (1973)United States v. State Tax Commission of MississippiNo. 72-350Argued March 19, 1973Decided June 4, 1973412 U.S. 363SyllabusThe United States brought this action contesting the validity of appellee Tax Commission's regulation requiring out-of-state liquor distillers and suppliers to collect and remit to the Commission a wholesale markup on liquor sold to military officers' clubs and other nonappropriated fund activities located on bases within Mississippi, over two of which the United States exercises exclusive jurisdiction, and the remaining two of which concurrent jurisdiction.  Relying on the Twenty-first Amendment, the District Court upheld the regulation.Held:1. The Twenty-first Amendment does not empower a State to tax or otherwise regulate the importation of distilled spirits into a territory over which the United States exercises exclusive jurisdiction, Collins v. Yosemite Park & Curry Co., 304 U. S. 518, regardless of whether some of the liquor may have been consumed off base.  Pp.  412 U. S. 369-378.2. Whether the markup can be viewed as a sales tax to whose imposition in the context of the two exclusive jurisdiction bases the United States has consented under the Buck Act and whether, in any event, the markup unconstitutionally taxes federal instrumentalities, and violates the Supremacy Clause as conflicting with federal procurement regulations and policy are issues that the District Court did not reach and should consider initially on remand.  Pp.  412 U. S. 378-381.340 F. Supp. 903, vacated and remanded.MARSHALL, J., delivered the opinion of the Court, in which BURGER, C.J., and BRENNAN, STEWART, WHITE, BLACKMUN, and POWELL, JJ., joined.  DOUGLAS, J., filed a dissenting opinion, in which REHNQUIST, J., joined, post, p.  412 U. S. 381. Page 412 U. S. 364