Native American groups are protesting the Medford Public Library’s decision to auction off a collection of Native American artifacts next month and questioning the legality of the sale.

In a public notice posted Nov. 13, the library said a collection of 19th-century Pacific Northwest Indian artifacts it described as “surplus goods” would be sold Dec. 1 in Boston by Skinner Auctioneers and Appraisers.

“This auction is unconscionable in a country with laws and obligations such as the Native American Graves Protection and Repatriation Act,” said Jean-Luc Pierite, president of the board of directors of the North American Indian Center of Boston. “The provenance of these artifacts includes the prayerful way in which they are made, and a gifting process which is indicative of a sacred bond. To sell these items for short-term profit without proper consultation on repatriation is part of the troubling disregard for government-to-government relationships."

The collection — donated to the library in 1880 by James G. Swan — includes two wood shaman’s masks that may have been made for the helper of a shaman, a person believed to have access to and influence in the world of good and evil spirits. Skinner estimates both masks are worth at least $30,000.

The collection also includes two shaman’s bird rattles valued at between $5,000 and $8,000; a shaman’s spirit figure estimated at $4,000 to $6,000; a cedar trunk expected to fetch between $3,000 and $5,000; and a cedar totem pole valued at $800 to $1,200.

Library Director Barbara Kerr declined to comment on why the library is selling the artifacts or whether she or Skinner, which did not return calls yesterday, had tried to contact the tribes from which they originated, as required under the 1990 Native American Graves Protection and Repatriation Act, according to to Raquel Halsey, the executive director of the North American Indian Center of Boston.

“Auctions around the world have sold Native American artifacts, property often either stolen or traded out of the need for food, shelter and other basic necessities,” said Halsey, a member of the Mandan, Hidatsa and Arikara Nation. “It’s our hope that people at institutions like the library would be more enlightened. They’re supposed to be repatriating these items back to the nations they came from, and the onus is on the institutions to make contact with the tribes.”

Once that happens, the tribes may take possession of the artifacts or allow the institutions to take stewardship of them, provided they take proper care of the items, she said.

Janeen Comenote, executive director of the National Urban Indian Family Coalition in Seattle, said such auctions are not uncommon.

“Oftentimes, collectors just don’t know the meaning of the artifacts,” said Comenote, a member of the Quinault Indian Nation. “Often, these were procured by violence or left behind at camps where there were massacres. But however they were acquired, any item taken from another culture should be treated with respect.”