Not sure what this Heuchera is, any ideas?

Many years ago i came across this plant while exploring a remote area of limestone outcrops in central Idaho. It seems the population was only on cliffs in a rather small area and was a bit of a hectic climb just to have a look(i could not repeat that today, i'm afraid). I am not really sure what it is as i have not been able to key it out in a satisfactory way and have never been skilled with keys anyway. It will only grow in the most austere conditions, like rock crevices and seems to die quickly in any other medium. Here are a couple of pictures in my garden, not very good pictures, they do not really show just how red the flowering stems are. Just sort of curious if anyone knows this one.