[Maru]

13 miles I know of at least, because I tracked it once... I'm sure I've walked more at Six Flags or something though.

There is an extensive trail system in the Northeast, and the husband and we made it to 13 miles one time just picking random places to go to extend it and marking it with GPS... and one time accidentally ended up coming out the back side of a friend's apt, so we paid him a visit and then walked home. Which was kind of funny in it's randomness (and he was actually home that time!)