Oregon Zoo officials in Portland say archaeologists have recovered the remains of nine people since construction crews digging a trench on zoo property found a human skull in mid-August.

After that initial discovery, the zoo notified the Oregon State Historic Preservation office. Construction work in the area was halted during the investigation and recovery effort.

Heidi Rahn directs the Better Zoo Program, which oversees construction funded by a 2008 zoo bond. She said Friday the remains are believed to be residents of a poor farm operated by Multnomah County more than 100 years ago.

She says officials hope to rebury the remains close to where they were found.

The zoo says the Hillside Farm was a 160-acre poor farm that operated from 1868 to 1911 in a portion of Washington Park now occupied by the zoo, an arboretum and a forestry center.