Harmony Hall Mansion is closed to the public. There are the ruins of multiple historic structures on the site. These ruins are unstable so do not enter or climb on any of them. Also be aware of fencing remnants, including barbed wire.
During warmer months, ticks are very common in the fields, forest, and wetlands surrounding Harmony Hall. Long sleeves and pants are suggested. Also, check for ticks at regular intervals.
Do not feed or touch wildlife. If you encounter wildlife acting aggressively or erratically, keep your distance and contact ranger staff at (301) 763-4600 immediately.