I am wondering what species of butterfly/moth caterpillar this one is. I photographed it at the Arboretum in late July.
Hennepin County Minnesota caterpillar identification
Thanks for the question, Unfortunately I am not able to provide you a precise identification due to an inability of seeing the entire caterpillar. Often there are identifying characteristics that are only evident when the entire body's color pattern can be seen. Also distinguishing characteristics are sometimes located at the posterior end of the body. Your picture only shows the anterior end. My best guess is that it is a moth caterpillar, possibly one of the many species of sphinx moths.
Sorry for not being able to fully answer your question.