Rock Creek Park is preparing for a hauntingly good time at its eighth annual Trunk or Treat festivities on Halloween. It will be held from 4 to 6 p.m. on Oct. 31. The family-friendly event began at the park eight years ago as a way to provide children in the community a safe place to trick-or-treat in a well-lit and traffic-free environment. Admission and parking are free and all ages are welcome.