Etna Furnace, in Catherine Township, Blair County, was the first iron furnace in Blair County, built in 1809 by John Canan, David Stewart, and William Moore.   It was later sold to Henry Spang.   After Spang's death, it was purchased by Samuel Isett.   After the canal closed in 1872, the iron business declined and finally shut down in 1876.   Etna Furnace is one of the most complete standing today, although they are privately owned.   The Blair County Historical Society was deeded the land on which the furnace stack sits in 1947.   In 1990, steel bands were placed around the stack to prevent further collapse.