- Elk populations exploded, resulting in severe overgrazing of the willows and aspens needed by beavers for food, shelter and dam building.
- Scavenger species suffered population reductions because they did not have year-round wolf kills to feed on.
- Beavers virtually disappeared. Dams disintegrated, turning marshy ponds into streams. Heavy stream erosion resulted, with many plant and animal species being adversely affected.
- Without wolves, the coyote became the apex predator, driving down populations of pronghorn antelope, red fox, and rodents, and birds that prey on small animals.