The idea is to have a set of unified rules already in place for Siege the Hills owned terrain. This should save you time in discussing it with your opponent and cut short any disputes about what terrain means what game rule.
Linear ObstaclesThese are pretty self explanatory. They are treated exactly as detailed in Prime or Primal under Linear Obstacle. They provide Cover as they are made of rock.
Rock MesaThe Rock Mesa is an Obstacle. It takes extra move to get on to it but is open ground once you're on it. +2 DEF against melee attacks if you're partially obstructed by it. It also will provide Elevation once you're on it. You can take Cover behind it.
The TowerThe Tower is an obstruction plain and simple. It provides cover. You cannot enter or destroy it (even if you really want to).
If you need further explanation of the terrain let me know and I'll update this post. I'll also add to it any time we make more terrain for the table.