Rocky Mountains have young and tall mountains with high elevations.It stretches from Alaska to New Mexico. From a scale from 1 to 10 I give it a 4. I give it a 4 because it would be very hard to run in and it does not have a big water source and it does not have a good food source. But it has some great hiding places.
The Great Plains flat lands that elevate westward. Plains are flat land that have very little trees. I give it a 5 because it would be easy to move through but you really can't hide anywhere and it is very dry so you might get dehydrated before the zombies get to you. so if I were going to the Great Plains I would pack a lot water.
The Interior Lowlands has rolling flatlands , rivers ,and broad valleys. It has very grassy hills. I would the Interior Lowlands a 8. I would rate this an 8 because it has lots of water sources so you don't get dehydrated and you can move easily and it would be a little difficult to find a hiding place you can still find one. I really recommend being hear if there was a zombie apocalypse.