50
Because the US covers a large area of land with contrasting climate regions.
10 land regions
4 main land regions
Illinois has 3 land regions.
Nebraska has 49 land regions
2 main land regions
Nogeroa has 10 land regions.
three main land regions
There are 4 main land regions.
the great basin
There is three land regions in Costa Rica.
Vermont has six (6) main land regions.