As of late I've spent the majority of my time riding in nearby Elm Creek Park. It's part of the Three River's Park District here in the Twin Cities. Those of us that live here in the "Big City" as northerners would call it, are very fortunate to have access to so many beautiful parks.
Soon, we will have another new single track trail system nearby. Practically right in our back yard. For some us that are more fortunate this statement is literally quite true. In the meantime, while we wait, many of us have using the existing trails as our training/playground. I'll be posting a bit on this new trail system soon.
In the meantime, I hope that you're getting out and putting in some ride time.