If you have never had a chance to get to Sax-Zim Bog in northern Minnesota it is a trip worth making. In fact it is a trip worth making several time over the year. Winter specialties include northern owls, most notably Great Gray Owls and Northern Hawk Owls. Summer is good for nesting warblers including Connecticut Warblers. Spring is a good time to look for Sharp-tailed Grouse and Fall migration can produce almost anything if you're in the right place at the right time.
Even if you can't make it visit the website for the area and see what you're missing!