Opinion of the Court
Here, the Yakamas’ lone off-reservation act within the State is traveling along a public highway with fuel. The tax thus operates on the Yakamas exactly like a tax on transportation would: It falls upon them only because they happened to transport goods on a highway while en route to their reservation. And it is the practical effect of the state law that we have said makes the difference. We held, for instance, that the fishing rights reserved in the treaty pre-empted the State’s enforcement of a trespass law against Yakama fishermen crossing private land to access the river. See, e. g., United States v. Winans, 198 U. S. 371, 381 (1905). That was so even though the trespass law was not limited to those who trespass in order to fish but applied more broadly to any trespasser. Put another way, it mattered not that the tax was “on” trespassing rather than fishing because the tax operated upon the Yakamas when they were exercising their treaty-protected right. Ibid.; see also Tulee v. Washington, 315 U. S. 681, 685 (1942) (holding that the fishing rights reserved in the treaty pre-empted the State’s application of a fishing licensing fee to a Yakama fisherman, even though the fee also applied to types of fishing not practiced by the Yakamas). And this approach makes sense. When the Yakamas bargained in the treaty to protect their right to travel, they could only have cared about preventing the State from burdening their exercise of that right. To the Yakamas, it is thus irrelevant whether the State’s tax might apply to other activities beyond transportation. The only relevant question is whether the tax “act[ed] upon the Indians as a charge for exercising the very right their ancestors intended to reserve.” Tulee, 315 U. S., at 685. And the State’s tax here acted upon Cougar Den in exactly that way.
For the same reason, we are unpersuaded by the Department’s insistence that it adopted this tax after a District Court, applying this Court’s decision in Chickasaw
