sory to the one who posted that no north american snake will reach 12 ft
bull snakes can and do (quite frequently) reach that length , i know this from peorsonaly mesuring them (not eyeblling it but realy measuring them )like king snakes their food suply and enviroment will be contributing factors on how big they will get , i used to work for some one that would go nd remove them for people and relocate them to frms for rodent controll, in one 12' x 28' wood pile we found 3 @ 12' and 6 reaching 10'
in tht pile there we over 150 bull snkes
on 10 acres over run with rodents , bull snkes eat rattlers, copperheads and water mocasins as do king snakes