Upper Peninsula Caterpillar (who?) brown w black chevrons

These guys/gals are all over right now in the U.P. of Michigan. We've had an unusually warm and early spring, so everything is a bit early hatching and budding out. I have seen a lot of these lately, and they seem to like our front and back door. I'll post some pictures, because I've tried looking them up on enature (my primary ID website) and this new place I found (Discover Life), but no luck. Also skimmed the most recent posts here in case someone else has noticed them and asked. Fully expecting them to be some obvious critter I've overlooked, but I just cant figure them out!
We have a lot of pine (jack, red, and white), spruce (black and white), balsam fir, northern red oak, sugar and red maple in the area, as well as back yards on sandy soil. Hoping that might help. I'm wondering if this is a species that has a sort of boom-bust life cycle? I am seeing a lot of what I think are morning cloaks in the woods, but they are adults. Also think I've ID'd a spring azure (closest I can get, and will post that for confirmation next).

These two were on my front step, fixin to get squished if I didn't move them. So, I picked them up and my camera and took some pictures. I've got about averate sized hand for a medium sized female, for size comparison.

Here is another image. There were two on my hand, but they headed in different directions once they uncurled from their tight little c shape of terror at being picked up by something big and scary.

Last image for now. Thanks everyone for helping. One of these days I'll be able to identify something for someone else and 'give back' to the forums. Everytime I recognize something, someone else gets there first. sigh.
Anyway, thanks y'all!

This is a larva of a moth in the family Noctuidae (cutworms, armyworms, etc.) - see http://tinyurl.com/9xk982 for an example.

Thank you very much, Suunto! I have a starting point now, and I think I'm going to have to hit the library (and maybe the local college insect professor) and see if I can get any more specific. Once I figure out what it is more specifically, I might post it in the Files here for insects for other people to see. I'll definitely say thanks to all who helped me, 'cause I couldn't get closer than I'm sure it's a caterpillar and I know it's not anything I've seen before (e.g. monarch and easy stuff like that).
I tried google image searching for
(noctuidae OR noctuid OR cutworm OR armyworm) (larvae OR larva OR catterpillar) -"western -bean" -"beet -armyworm" -"black -cutworm" -"true -cutworm" -"true -armyworm" -"fall -armyworm" -"common -armyworm" -"northern -armyworm"
Because just the first sets in parenthases came up with a crazy number of hits (and a lot of repeats of the more common ones). Even knocking out the kinds that came up most often and were definitely not my little crawlies came up with over 50 pages of image results to view... which I did. So, I'm still off to the library!
Thanks again!