<Li> Crotalus oreganus cerberus, Arizona black rattlesnake </Li> <Li> Crotalus oreganus concolor, Midget faded rattlesnake </Li> <Li> Crotalus oreganus helleri, Southern Pacific rattlesnake </Li> <Li> Crotalus oreganus lutosus, Great Basin rattlesnake </Li>

How many types of rattlesnakes are there in the us