I'll admit that in my fascination with the squirrel family (including chipmunks, marmots and prairie dogs) and animated rodents (usually mice and rats), I didn't give much thought to the possibility of seeing a porcupine until we were well into Wyoming and even then I had to check that they were rodents (they are).
So, after seeing three dead on the roads of Wyoming and Montana, we started looking for live ones at Devil's Tower.
The Mister has a rather magical way with wildlife. I've seen more animals with him than in all of my life previous. If anyone could see a porcupine by force of will, it would be the Mister and it would have been at Devil's Tower, where we hiked late into the evening and every pine made sounds (bark beetles?). But no.
So we still haven't seen one of the second largest rodents in North America alive, but two people yesterday mentioned seeing live ones recently and tomorrow we are headed to the Porcupine Wilderness, so we'll see.
Completely unrelated, we have a new mystery animal. Over near the Michigan border yesterday, a mammal bounded across the road. While unlike the teaser animal (answer to the teaser in the comments below), this animal we had seen in zoos. It's larger than a white tailed prairie dog, smaller than a moose, faster than a golden mantled ground squirrel and slower than the a pronghorn antelope.