Photo by Graham Cullen Auctioneer John Roop assembles an antique butter churn, next to an 1890s milking machine patented by William Mehring of Keymar, which will be auctioned Saturday in Woodsboro. Purchase this photo

These and many other items will be available at the dairy auction on Saturday in Woodsboro .

"This will be the auction of all dairy auctions," said 81-year-old Olive McGovern, the owner of the extensive collection.

In 1986, McGovern and her husband, Hugh, began collecting the items from a mixture of auctions, yard and antique sales and flea markets. When Hugh died in December at the age of 71, McGovern decided to auction the collection. She turned to a longtime friend, auctioneer John Roop.

Hugh McGovern has "been in the industry since college," Roop said. "He started in New York, and he always either drove a milk truck delivering or worked in the dairy plants."

Roop, owner of Roop's Auction Service, has been in the business for 15 years. He is the president of the Frederick County Auctioneers Association and sits on the board of directors of the Auctioneers Association of Maryland.

"I grew up on a 400-acre dairy farm in the New Windsor, Libertytown area, so I've been around auctions all my life," Roop said.

The auction has taken about eight months on and off to organize, Roop said, and consists of thousands of pieces. There are more than 2,500 milk bottles from a variety of farms, including one of five existing 1890 embossed milk preservative jars from Washington. Other items include advertisements, cream separators and churns.

"The crowd will work you down to nothing to try to get a deal, and then you'll work right back up," Roop said of the auction process.

Roop and McGovern are expecting hundreds of people from at least 15 states. One man called to inquire about a piece in the collection he has been hunting for 30 years, Roop said.

Along with Roop, Randy "Judge" Smith has been instrumental in organizing the auction, McGovern said.

"He was Hugh's boss at Trans-Tech for 10 years, and he's a really good friend," she said.

Saturday's auction will be run by three auctioneers. Phone and absentee bids will be accepted, but online bids are not available. There will be no buyer's premium.

As Roop and McGovern sifted through the collection, Roop remarked on the work cut out for him.

"Thank God (Hugh) didn't have eBay."

He laughed.

"EBay has hurt the auction market, but live auctions are very fun," he said. "We try to keep it upbeat and have a good time."

The rare and aged nature of these items and the Frederick County connection provide incentive for attendance, Roop said.

"Come and get a piece of local history," he said. "There are other large milk bottle collections, but as far as dairy collections, I think you're looking at the largest collection in the state of Maryland."