Hmph, I was afraid you'd say that. Wikipedia people are hard to get a hold of, and even harder to convince. They really remind me more and more lately of an insurance company... "SOP is to deny all claims no matter the circumstance. If they hassle you, bump them to another representative..."
Anyway, from someone who actually lives in the Midwest, Tornado Alley should be at the very least extended, if not shifted approximately 350 miles east.
EDIT: Okay I checked out the Wiki article and it's actually not complete fiction as I feared. That map that Evil D showed is pretty junky, but they have another one below it (ironically enough) that shows a much more accurate depiction based upon actual reported tornados (or maybe measured? There is a big difference, sadly) rather than made-upish metereological guesswork.
Here's a decent map of Tornado Alley from wikipedia:

As you can see, New Mexico doesn't have any reported significant tornadoes, and Colorado has very few. The Dakotas as a region are also non-contenders, even though the article muddles around the definition so much that one might be inclined to include it.
In fact, Tornado Alley covers nearly the entire Midwest from Kansas to Ohio, except for the northernmost parts near Canada. It also covers the heart of the Deep South. Nothing in the West, however, or New England.
I should've known about Kentucky, I have a cousin there and now that I think about it they've suffered through some tornadoes that have left them without power for days at a time.
Louisana and Alabama are the only real surprises to me, I didn't know that they got tornadoes that far south... I thought they just got hurricanes.
Anyway, the article is pretty lousy overall as a source of information; the only real thing that one can glean is that the author(s) feel that there is no consensus definition (thanks, guys). This about a phenomenon that has a goo-gob of solid regional scientific data sitting around (despite the rather existential definition that meterologists use for a tornado). The author just shakes his head and says, "well, shucks... there's no
official definition, and different media yahoos say different stuff... guess we're outta luck." Can we say lazy writing?
If you want to find info on Tornado Alley, carl, I'd look elsewhere, or use the map I posted as it's about the only worthwhile thing from the article.