Hi guys, I want to preface that this is the first time I’m dealing with animation in UE4, so I’m completely new to that side of things, in case this seems like a very basic question to you guys. I’m trying to set up different “zones” where when a character moves into them, the animation changes. For example, if he’s walking and then there is a downward slope, I’d like to put a field in there that when entered would cause him to enter his crouch / slide position. If there is also a way to change controls based on the zone as well then that would be great, but that I can probably figure out based on the animation change. Thank you very much! 
Create an enumeration (In Content Browser, New->Bluprints->Enumeration) that stores all possible states a character can be in. For example, Crouching, Sliding, Vaulting, Prone, etc.
Create a variable of that enum type in your Character blueprint. When you know your character needs to change state, set that enum variable appropriately in your Character blueprint, read that variable from the Character in your Animation Blueprint and use it to blend between the different Animation States.
To change controls, you make use of the same enumeration to switch between keys and their corresponding action in your Character blueprint. Use the ‘Switch’ flow control in Blueprints for this.