The Great Plains are a flat area of land with little to no increases of elevation and they have dry grasslands. I rate this region 5 because it is flat witch means the zombies can get you easier but it does have resources. A geographical feature in this region are plains.
The Canadian Shield has the Great Lakes along with hundreds of other lakes carved by melted glaciers it also contains some the oldest rock formations. I rate this region 8 because it has resources. A geographical feature in this region are lakes.
The Rocky Mountains are tall rugged mountains containing the Continental Divide . I rate this region 9 because zombies can't climb fast. A geographical feature in this region is mountains.