[codingdave]

The gist of your point is correct, but "West of the Mississippi" is the wrong dividing line. You have about a state and half of excellent land west of the Mississippi. It is all about the mountains - From when the mountains start just past the West coast, they cause clouds to dump their moisture on the west side. The east sides are arid, for a couple hundreds miles or more. And because we have multiples ranges of mountains, the western third of the nation is arid... with pockets of agriculture just west of each mountain range.

[mitchty]

Indeed, calling the Dakotas/montana as "desert" is... misleading.

Tundra maybe, but its not really a desert. And the plains are a great spot for grazing critters like Bison. The land there is their old stomping grounds, they fit in there like jelly on peanut butter sandwiches.

[AnimalMuppet]

It's not just "a couple hundred miles past the mountains". It's basically even with the western edge of the Gulf of Mexico. East of there, there's enough rain. West of there, there's not.

[rsj_hn]

You are right that "West of the Mississippi" is not the actual boundary, which is why I said "majority of the land". The actual boundary curves, being farther west in the Gulf and almost touching the Mississippi in the North, but "Western half of the US" is as good a description as any.

Point being, a lot of people who grow up in the Eastern Half of the US think the Western half has a similar climate, when it really doesn't. It really is an arid climate and the difference between East and West is rather stark.

Here you can take a look at a map of precipitation:

http://www-das.uwyo.edu/~geerts/cwx/notes/chap17/rain_usa.ht...