Depends on your definition of "off-roading". There are a ton of forest roads up north that are a little challenging. And a few things here and there that are designated ORV usage, but aren't really challenging. The only really good stuff is in Gilbert, MN. The Iron Range Off Highway Vehicle Recreation Area. A picture of our bone-stock '04 Outback on our last trip up there (actually my wife was driving then) And my 4.3Runner on one of the really challenging trails last year.
I'd be interested in something around the cities if anyone knows of an easy trail or spot. I just lifted my legacy a few inches and would love to see what it can do. Mike