"While Congress certainly may by law prohibit and punish the entry upon or use of any part of those forest reserves for the purpose of the killing, capture or pursuit of game, this would not be sufficient. There are many persons now on those reserves by authority of law, and people are expressly authorized to go there, and it would be necessary to go further and to prohibit the killing, capture or pursuit of game, even though the entry upon the reserve is not for that purpose. But, the right to forbid intrusion for the purpose of killing, _per se_, and without reference to any trespass on the property, is another. The first may be forbidden as a trespass and for the protection of the property; but when a person is lawfully there and not a trespasser or intruder, the question is different. "But I am decidedly of opinion that Congress may forbid and punish the killing of game on these reserves, no matter that the slayer is lawfully there and is not a trespasser. If Congress may prohibit the use of these reserves for any purpose, it may for another; and while Congress permits persons to be there upon and use them for various purposes, it may fix limits to such use and occupation, and prescribe the purpose and objects for which they shall not be used, as for the killing, capture or pursuit of specified kinds of game. Generally, any private owner may forbid, upon his own land, any act that he chooses, although the act may be lawful in itself; and certainly Congress, invested also with legislative power, may do the same thing, just as it may prohibit the sale of intoxicating liquors, though such sale is otherwise lawful. "After considerable attention to the whole subject, I have no hesitation in expressing my opinion that Congress has ample power to forbid and punish any and all kinds of trespass, upon or injury to, the forest reserves, including the trespass of entering upon or using them for the killing, capture or pursuit of game.