The barn at the historic Ross Farm in Washington County was destroyed in a late-night fire.
Dispatchers said the blaze was reported around 11 p.m. at the farm on Route 519 in North Bethlehem Township with reports of animals possibly inside.
An unknown number of sheep are believed to have perished in the fire.
Marianna VFD were among the crews that responded.
The Ross Farm is listed on the National Registry of Historic Places and is known for heritage and rare breed wool.