My wife and I were in the area and stopped by. I am uploading Mapillary imagery that which shows there is only a small sign at the entrance of "The Dump" trail.

The County's map shows the trail is within Stuart's Landing Park. 
https://arcg.is/184HyW

Property map shows it is sevaral parcels belonging to the City of Marshall.
http://link.fetchgis.com/61b507bf

The "The Dump" park should be removed. The real park should be expanded to match its full boundaries. A MTB trail relation should be created. The trail's name should be on its relation, not its segments. The sign could be mapped as its trailhead. Once the Mapillary imagery has processed, the photos could be used for adding details.