ST. LOUIS (AP) -- Workers on the grounds of the new Vashon High School made a discovery that calls for breaking out the champagne -- literally.

A company doing exploratory excavation work at the St. Louis site recently uncovered a vast underground cellar believed to be part of the old American Wine Co.

"This is a national treasure," said Larry Giles, an architectural historian familiar with the site. "These are the largest underground champagne cellars ever built in the U.S."

Giles, who operates St. Louis Architectural Art Co., helped salvage some of the site's relics when the original winery building was demolished in the late 1970s.

He said he believes the cellar is 100 feet by 200 feet, and 50 feet deep. When he heard about the School Board's plans for the site, he told one of the project contractors who passed on the word to school officials.

School officials said they had soil borings conducted on the site, but never detected the cellar.

Last week Bellon Wrecking and Salvage of St. Louis began digging up the first level of the cellar. It had apparently filled in with debris after the original building was demolished.

Giles said he believes the cellar consists of three levels. Workers for Bellon pumped water out of the lower two levels Friday.

It's not know when the cellar was built, but Isaac Cook founded American Wine Co. in 1859. Cook, a political activist and former postmaster of Chicago, supported Stephen A. Douglass and President Franklin Pierce. By 1875 the company was selling a half million bottles of champagne annually.

School officials aren't sure the cellar could be saved.

Glen Vandelicht, who oversees buildings and grounds for St. Louis Public Schools, said the school system plans to send experts into the lower levels once the water is pumped out to assess the site's archaeological significance.

A parking lot is scheduled to sit on top of the wine cellar, so the discovery won't delay construction of the school itself, Vandelicht said.

The site for the school takes in 21 acres and will accommodate about 400 more students than the existing school. Officials are hoping the new high school will lure some students back to the city who are bused to county schools as part of a desegregation plan.

Keith Northway, a history teacher at Vashon, visited the site he heard about the find. He said he hoped the site could be saved and used for his classes.

"It would be a one-of-its-kind in the U.S.," Northway said. "It would be like a living classroom beneath your school."