Creek is signed just like river, and it is a multi-part sign. First, make the sign for water with your dominant hand (by tapping the ASL letter 'W' against your chin), then hold your hand open and flat, palms facing each other in front of you, running parallel to each other as they shimmy in a synchronized curved manner, somewhat similar to how you sign hall or street, but in a sinuous way instead.
This sign for creek or river is also the sign for stream.
Teach your baby or toddler the creek sign when you are actually out for a stroll in the woods, at a park, or in your very neighborhood, and you are lucky enough to have a creek running through it.
We use the sign for creek when we have one in close proximity to home.