Mr. Edmond G. Toomey, of Helena, Mont., for appellant.
Mr. Clarence Hanley, of Helena, Mont., for appellees.
Mr. Justice RUTLEDGE delivered the opinion of the Court.
Again we are asked to decide whether state taxes as applied to an interstate motor carrier run afoul of the commerce clause, Art. I, 8, of the Federal Constitution.
Two distinct Montana levies are questioned. Both are imposed by that state's Motor Carriers Act, Rev.Codes Mont.(1935) 3847.1-3847.28. One is a flat tax of $10 for each vehicle operated by a motor carrier over the state's highways, payable on issuance of a certificate or permit, which must be secured before operations begin, and annually thereafter. 3847. 16(a).1 The other is a quarterly fee of one-half of one per cent of the motor car- [332 U.S. 495 , 497] rier's 'gross operating revenue,' but with a minimum annual fee of $15 per vehicle for class C carriers, in which group appellant falls. 3847.27.2 Each tax is declared expressly to be laid 'in consideration of the use of the highways of this state' and to be 'in addition to all other licenses, fees and taxes imposed upon motor vehicles in this state.'
Prior to July 1, 1941, the fees collected pursuant to 3847.16(a) and 3847.27 were paid into the state treasury and credited to 'the motor carrier fund.'3 After that date, by virtue of Mont.Laws, 1941, c. 14, 2, they were allocated to the state's general fund.
Appellant is a Kentucky corporation, with its principal offices in Indianapolis, Indiana. Its business is exclusively interstate. It consists in transporting household [332 U.S. 495 , 498] goods and office furniture from points in one state to destinations in another. Appellant does no intrastate business in Montana. The volume of its interstate business there is continuous and substantial, not merely casual or occasional. 4 It holds a certificate of convenience and necessity issued by the Interstate Commerce Commission, pursuant to which its business in Montana and elsewhere is conducted.
In 1935 appellant received a class C permit to operate over Montana highways, as required by state law. 5 Until 1937, apparently, it complied with Montana requirements, including the payment of registration and license plate fees for its vehicles operating in Montana and of the 5õ per gallon tax on gasoline purchased there. 6 However, in 1937 and thereafter appellant refused to pay the flat $10 fee imposed by 3847.16(a) and the $ 15 minimum 'gross revenue' tax laid by 3847.27. In consequence, after hearing on order to show cause, the appellee [332 U.S. 495 , 499] board7 in 1939 revoked the 1935 permit and brought this suit in a state court to enjoin appellant from further operations in Montana.
Upon appellant's cross-complaint, the trial court issued an order restraining the board from enforcing the 'gross revenue' tax laid by 3847.27. But at the same time it enjoined appellant from operating in Montana until it paid the fees imposed by 3847.16(a). On appeal the state supreme court held both taxes applicable to interstate as well as intrastate motor carriers and construed the term 'gross operating revenue' in 3847.27 to mean 'gross revenue derived from operations in Montana.'8 It then sustained both taxes as against appellant's constitutional objections, state and federal. Accordingly, it reversed the trial court's judgment insofar as the 'gross revenue' tax had been held invalid, but affirmed the decision relating to the flat $10 tax. Mont., 172 P.2d 452, 460.
We put aside at the start appellant's suggestion that the Supreme Court of Montana has misconstrued the state statutes and therefore that we should consider them, for purposes of our limited function, according to appellant's view of their literal import. The rule is too well settled to permit of question that this Court not only accepts but is bound by the construction given to [332 U.S. 495 , 500] state statutes by the state courts. 9 Accordingly, we accept the state court's rulings, insofar as they are material, that the two sections apply alike to interstate and intrastate commerce and that 'gross operating revenue' as employed in 3847.27 comprehends only such revenue derived from appellant's operations within Montana, not outside that state.