While shopping around online for materials to make necklaces, I came across sales for teeth from animals such as coyotes, wolves, and bobcats. As a resident of Idaho, would it be illegal for me to possess or purchase these items?
Coyote, wolf, bobcat teeth possession and sale?
Animals are classified differently and there are different rules regarding possession and sale depending on the classification.
This answer is specific to the species you describe.
Coyotes are predators and can be possessed and sold at any time.
Wolves are big game animals. The sale of legally taken hides, horns, or heads of game animals, when detached from the carcass, and mounted wildlife, where sale is not specifically prohibited by federal statute or regulation or state statutes, shall be lawful only when the wildlife to be sold is accompanied by a statement showing that the animals were lawfully taken. It shall be lawful to possess or sell naturally shed antlers or horns of deer, elk, moose, antelope and mountain goat, and antlers or horns of deer, elk, moose, antelope and mountain goat which have died from natural causes.
Bobcats are classified as furbearers. The sale of pelts and parts of furbearers when legally taken shall be lawful.