Idaho Law Permits Selling Roadkill Art

In Idaho you can purchase or sell wildlife parts, but not the meat of big game, upland game, up birds or furbearer's that are lawfully hunted or trapped that have been killed in vehicle-collisions. Bighorn sheep can't be purchased, bartered, or sold. The Idaho animal artist or taxidermist when finding roadkill can consume the meat but never sell the meat. The fur and bones can be used for art and legally sold in Idaho. 

It is illegal to collect, possess, or transport roadkill jackrabbits in California, making their use for taxidermy unlawful. California law currently prohibits the collection and possession of dead wildlife, including roadkill, without specific authorization. To legally have a jackrabbit taxidermied in California, the animal must be taken legally during its open season and possession limits, as there are no bag limits for jackrabbits. The taxidermist must maintain records for one year, including the owner's information and details of the specimen, and must also be able to produce the specimen for inspection by law enforcement. Legal take for CA: The jackrabbit must be taken legally. In California, jackrabbits can be taken year-round with no bag or possession limits. 

In CA it's legal to hunt a jack rabbit and mount it, it's illegal to pick up jack rabbit roadkill and mount it.