Yep. The sky doesn't reflect much IR, whereas the red cliffs reflect a lot, providing for that high contrast environment. You could in theory achieve a similar result in classic B&W photography by using a dark red filter, but the result would not be nearly as dramatic or alien. Good question.
It would be interesting to try this same shot in B+W w/red filter over the lens. The foliage would become more prominent which might not be a bad thing but the sky would remain very dark.
My biggest problem is that I'm not really into IR photography, in general. It may be because of Shirakawa's "Eternal America" which contains many, many B+W IR film shots. I liked his color, but hated his IR.
You're not the first person to tell me they can't dig IR. I've been experimenting off and on with a 3-stop Red filter on my digital, but I'm not getting results like you would expect with B&W film. I think I need to take some custom white balances, just like you need to do to be successful with IR, but I've been too lazy. The beauty of digital is that you can just open a color photo in PS and select your Red channel and you have pretty much what you'd get with a red filter and B&W film.
.8s @ F/8. I should have used F/11 if I wanted better clarity with this lens, but if the exposures get much above one second, you start to see ghosting in the center of the image, so I try to avoid that by stopping down. I also applied some (perhaps overzealous) passes of unsharp mask. Thanks for commenting.