Even before the creation of Yellowstone, the naturalist Henry David Thoreau and other supporters asked the government to protect nature and animals in that area. However, when the park was finally created, there was no such law. A law to protect most of the animals from being shot was not adopted until 1883, nearly 10 years after creating the park. Hunting "protected" animals were forbidden under that law. Nevertheless, poachers could still operate. So in 1894, a new law called the "National Park Protection Act" was adopted. The US Congress protected nature, wildlife and other natural resources. The new law forbade the killing or destroying of them, and only fishing was allowed. Nature, for example, trees, mineral resources, and other things, were not allowed to be harmed.