It's recored that over 2/3 counties of Missouri has the Eastern Hognoses. I take it that is what you are talking about because the other specie , the Plains ( a sub of the Western . ? ) is very hard to come by in Mo. with only a very few specimen found in only several counties. The Eastern Hogs are not commonly found as some other species of native snakes of Mo. even though they are abundant. All of my years of living and hunting in Mo. has only netted me several of actually finding them. My finds were always of the non-hunting > accidental kind as in particular where i use to live in Bates county on my property out in the boonies. Normally a creek or slow moving stream area they can be found but on my property, I had neither and in the 7 years living there i found 9. There is no really god way to find some species of reptiles other than the broad just plain hunting normal ways as in other species. Good luck........