Idaho has over 3000 native plants with 10 life zones extending from prairie to mountaintop. Characteristic evergreens are Douglas fir and western white pine. Other forest types include the oak/mountain mahogany, juniper/piñon, ponderosa pine, and spruce/fir. Syringa is the state flower while pine is the state tree. MacFarlanes four-o'clock, water howellia, Spalding's catchfly, and Ute ladies-tresses were the state's four threatened plant species as of August 2003.

Classified as game mammals are the elk, moose, white-tailed and mule deer, pronghorn antelope, bighorn sheep, mountain goat, black bear, mountain lion, cottontail, and pigmy rabbit. Rare animal species include the wolverine, kit fox, and pika. A total of 20 animal species were listed as threatened or endangered as of August 2003. Among them are the grizzly bear and bald eagle which are listed as threatened, while the woodland caribou, gray (timber) wolf, American peregrine falcon, and whooping crane are endangered.