These species all either begin their life with a pattern and lose it as an adult or they retain that pattern throughout their lifetime. 
That places them in the Patterned group. Click on the image to learn more about each one.

Broad-banded watersnake

Bullsnake

Coachwhip

Common watersnake

Copperhead

DeKay's brownsnake

Diamond-backed watersnake

Eastern hog-nosed snake

Great Plains ratsnake

Kansas glossy snake

Long-nosed snake

Northern cottonmouth

Plain-bellied watersnake

Plains hog-nosed snake

Prairie kingsnake

Prairie massasauga rattlesnake

Prairie rattlesnake

Racer

Scarletsnake

Speckled kingsnake

Texas nightsnake

Timber rattlesnake

Variable groundsnake

Western diamond-backed rattlesnake

Western milksnake

Western pygmy rattlesnake

Western ratsnake