Access terrain alphamaps directly? To clone them?

How do you clone a terrain's alphamap? It's inaccessible according to unity intellisense? In case anyone reading this doesn't understand: setalphamaps() changes all clones of the terrain. Not just the terrain you use it on. **The Solution:** Clone the alpha map. **The Problem:** Can't access the alpha map's Texture2D object. Hence this question being here.