Archaeologists working on a housing development found a prehistoric milling site estimated to be 8,000 years old, officials said.

Large, chunky arrowheads, stone slabs used to grind seeds and acorns, hearths and scorched rocks were among the items found at the site at the base of the Angeles National Forest.

No human or animal bones were discovered, according to archaeologists from Cogstone Resource Management Inc.

The Santa Ana consulting firm was hired by Azusa Land Partners, the company that's developing 1,250 homes on the 520-acre site.

Workers removed and catalogued about 100 tools and implements used by the Tongva, or "People of the Earth," who lived in the area before Europeans arrived.

"I'm very happy the proper steps are being taken in the preservation and recording of this very integral part of local and regional history," said Jeffrey Cornejo, chairman of the Azusa Cultural Preservation Commission. "I hope it will be celebrated and enjoyed by the public and used as a learning tool."

The area has been a known archaeological site since a study by the University of California, Los Angeles in the 1960s but the exact location was only discovered three weeks ago, said Sherri Gust, Cogstone's president.

The excavated portion measured about 50 yards by 80 yards and was 1½ yards deep. Work was completed Feb. 24.

The find won't delay home construction, said Bill Holman, a spokesman for Azusa Land Partners.

Azusa is about 30 miles east of Los Angeles.