Yellowstone was no exception to wolf reduction. Surrounding territories and states enacted wolf bounty laws and predator control programs that extended into the park. Elk and other prey carcasses were laced with strychnine or cyanide poison and left for a wolf pack to feed upon. In this way, entire packs could be destroyed. Another way to kill many wolves quickly was to capture a pup, tie it to a tree, and wait for pack members to hear its cries. The whole pack could then be shot as they attempted to come to their pup.