How many species of poisonous snake are in America?

There is a very poisonous lizard called the gilla monster.

I posted the wikipedia artice on the gilla monster in the related links box below.

first of all, its not poisonous, its venomous, there's a difference. Second, a Gila monster is not that venomous. its not fatal to humans. they are dangerous because they have very sharp teeth and they don't let go when they bite, causing major blood loss. the second and only other species of venomous lizard is the Mexican beaded lizard.