What species...they vary a lot between the smallest being Central Canadian Barren Ground Caribou not much more than a large mule deer to the largest, the Mt Caribou which are nearly elk sized. Woodland and Barren Ground are in between. So are Quebec Labrador but they are not being hunted the past few years.
I seriously doubt there are many 35" deep caribou out there....very large elk sized. That said, I don't have a good number for you....maybe check taxidermy supply forms and see what they run....if they list dimensions.