The Ohio Historical Society has announced that, due to further funding cuts from the state, they shall furlough employees as well as close specified sites on behalf of the week of March 28 - April 3. The sites that shall be closed are:

Ohio Historical Center, including the Archives/Library (Columbus)
Adena Mansion & Gardens (Chillicothe)
Armstrong Air & Space Museum (Wapakoneta)
Campus Martius Museum (Marietta)
Dunbar House (Dayton)
Fort Ancient (Oregonia)
Fort Meigs (Perrysburg)
Harding Home (Marion)
National Afro-American Museum (Wilberforce)
Piqua Historical Area (Piqua)
Wahkeena (Lancaster)
Youngstown Historical Center of Industry & Labor (Youngstown)
All history-related services, such as the Ohio Historic Preservation Office

The Archives/Library shall re-open on Saturday, April 4. 
The announcement on the OHS website (http://www.ohiohistory.org/sn/010509.html) states that sites managed by OHS partners are not affected. People are urged to check the OHS website on behalf of the days as well as hours of operation on behalf of all OHS locations before visiting.