Why are many of the local ranchers opposed to the wolves being reintroduced?

Wolves have a habit of taking the easiest prey. Domesticated animals are not only penned - where they can't run away and are always in the same area - they are not too bright when it comes to running away from danger. (We bred them to be fairly dumb because they're easier to work with that way). Certainly it's easier for a wolf to catch and kill a fat, overfed cow than a sleek and quick elk.

The life of a single steer or sheep is very costly to a rancher, who loses not only the value of the animal at market but the value of its potential offspring. However, the U.S. government has a program to compensate ranchers for animals killed by wolves, and laws exist to permit ranchers to shoot wolves that attack their livestock. Ranchers have occasionally made an (illegal) habit of baiting wolves so they can shoot them.

Hunters, especially elk hunters, are often opposed to wolf reintroductions because wolves decrease elk populations. While wolves will most often target the weakest animals, hunters strongly dislike the pressure on the species because it makes their seasonal pastime more difficult, less enjoyable, and less bountiful.

The reintroduction of wolves into Yellowstone National Park was a huge success for a number of reasons: it allowed a viable population of one of the park's formerly native animals to survive, and remarkably, vegetation improved as elk and deer were forced to change their grazing habits. However, as time has gone on, the wolf population has grown and expanded its range to a point where it is more frequently causing (expensive) problems for ranchers adjacent to the park. Part of the anger and frustration for the ranchers stems from the conflict between federal and local government (Yellowstone is federally-managed) as the federal government is seen as detached and uninterested in local affairs.

Wolf repopulation efforts have been successful in Minnesota and Wisconsin, and more wolves are appearing in the northern Rocky Mountains of Idaho and Montana. Although wolves are inconvenient to a few highly vocal individuals, it is worth recognizing that the wolf formerly lived throughout the United States but now inhabits only a few minuscule fragments of its former range. In the place of wolves, coyotes have expanded their range and now live in every U.S. state except Hawaii.