"Let me start by saying that I am not a herpetologist. This page is designed to list the venomous snakes of each state, but should in no way be considered an authoritative list. This page was compiled from information in the public domain, and has not been reviewed by a herpetologist."
...the preamble from the source, which is accurate in saying it should not be an authoritative list...
Not to be contrarian, but I'm somewhat skeptical of this list. 1) The author of the list denies that it's authoritative. 2) The line between species and sub species are rather blurred and most of the species listed would be considered to be subspecies. 3) The list is heavily skewed because of one person, Roger Conant. He was the first person to write a comprehensive taxonomy book on the reptiles and amphibians of North America. He was a professor at University of New Mexico and he spent most of his time cataloging species in the American Southwest. Most field herpetologists specializing in American snakes are connected to him. I spent a month in college running around south Oklahoma with one of his direct disciples and got lots of stories.
I am also skeptical of this list, at least as far as my own state of Missouri. The Missouri Department of Conservation lists only five venomous snakes for Missouri - copperhead, cottonmouth, timber rattler, western pygmy rattler, and massauga. I checked the source and it counts subspecies, too. The northern and southern copperheads on the list are subspecies, as are the western and eastern massaugas. Eastern massaugas are now considered extirpated from our state. The source still listed both of them but failed to include the prairie massauga which is another subspecies found in the state. The western pygmy rattler is a subspecies, too, but it's the only pygmy rattler found in the state and so should be counted. I prefer to go with the MDC list and leave the count at five. If one includes subspecies then seven would be correct, but the source is still incorrect as it includes the extirpated eastern massauga and does not list the prairie massauga.
I was not expecting California, because I live there and am familiar with our venomous snakes. The only venomous snakes we have are rattlesnakes--no copperheads, cottonmouths, or coral snakes. But I guess when every rattler subspecies is counted separately, they add up.
Yea I think we have the same in the Netherlands, 3 species, only one venomous, the adder, which if I search it in wikipedia and then switch to finnish I get a page with kyy.
...the preamble from the source, which is accurate in saying it should not be an authoritative list...
Guessing Southern states and/or states with hot temperature helped to get them all. It was a surprise that Florida is not on the list.
It would have been a big surprise to see Alaska on the list. We have in Finland only one venomous snake species, viper (kyy in Finnish).