In the entire United States, there are only 4 venomous snakes:
Rattlesnake
Copperhead
Water Moccasin
Coral Snake
Of those 4, Rattlesnakes are easy to identify with the rattles at the end of their tail & the large, triangle-shaped head. Coral Snakes are usually hidden & rarely bite, even when handled by people who don't know any better. And their Red & Yellow rings around their entire body is a warning.
The fact is, when venomous snakes are left alone, they don't attack. They know they'll starve for months while they make new venom, so they don't want to waste it on you - that's why they avoid people whenever they can.
Here is someone who tried to get 50 Rattlesnakes to attack him. Note their reactions: