8.1 miles. Easy to moderate trail surface; minor elevation change. Some muddy/rutted trail sections due to use by bikes/horses. The trail is mostly hard packed earth, with some rocky areas.
Our two cents: This park is more suited for shorter loops from one of the many parking areas; we stitched a bunch of trails together in order to see most of the park.
Update 11/9/15 - Directions revised and route modified slightly; photos added; revised GPX. Note: Some of the farm buildings have been demolished since the video was taken.