Prairie Rattlesnake
Crotalus viridis

Size:  3 - 4 ft
Western 1/3 to 1/2 of state.  The prairie rattlesnake, or western rattlesnake, prefers large open prairies littered with cover.  Its principle diet consists of the black-tailed prairie dog and utilizes prairie dog burrows as a retreat from danger and high temperatures.  According to recent LD50 analysis, this is the most venomous snake in the state.  Although it is extremely toxic, the prairie rattler is not known for aggression and will retreat when given the opportunity.