16 U.S.C. § 61

The Secretary of the Interior shall make and publish such general rules and regulations as he may deem necessary and proper for the management and care of the park and for the protection of the property therein, especially for the preservation from injury or spoliation of all timber, mineral deposits other than those legally located prior to the passage of the respective Acts creating and establishing said parks, natural curiosities or wonderful objects within said parks, and for the protection of the animals in the park from capture or destruction, and to prevent their being frightened or driven from the said parks; and he shall make rules and regulations governing the taking of fish from the streams or lakes in the said parks or either of them. He shall cause all persons trespassing upon the same to be removed therefrom.