A mother and daughter pleaded guilty Monday to several felony charges stemming from a sweeping federal investigation into the theft and illegal trafficking of American Indian artifacts.

Jeanne Redd, 59, pleaded guilty to seven federal counts of theft of government property, theft of tribal property and trafficking in stolen artifacts. Her 37-year-old daughter, Jerrica Redd pleaded guilty to three similar counts.

The pleas are the first from cases brought against 24 people in a two-year undercover investigation in Utah, New Mexico and Colorado.

In the sting operation, a confidential source paid more than $335,000 for 256 stolen artifacts, including bowls, stone pipes, sandals, arrowheads, jars, pendants and necklaces, according to court documents.

Both mother and daughter declined to comment Monday as they left the federal courthouse in Salt Lake City.

In court, in response to questions from U.S. District Judge Clark Waddoups, mother and daughter acknowledged their roles in the artifacts case in which the FBI and the federal Bureau of Land Management said they used a confidential source to buy stolen artifacts.

Jeanne Redd acknowledged three instances in 2007 and 2008 when she met the source at her home to discuss deals over an ax, gourd and necklace taken from prehistoric ruins on the Navajo Reservation, a turquoise pendant taken from BLM land and four sandals she dug up on U.S. Forest Service land.

Jerrica Redd acknowledged that in April 2008, she found a black and red pottery jar on the Navajo Reservation. Others she was with found a seed jar and a vase. She said she dug them up, took them back to her house, cleaned them and displayed them.

Prosecutors declined to speculate on what the guilty pleas will mean for sentencing — including whether they think the women will spend time in prison — except to say they will recommend something on the lower end of federal guidelines.

They said Monday's guilty pleas could affect others who have been charged and others thinking of illegally gathering ancient artifacts.

"I hope the message is that people will learn that we have sacred, stunning, rare unique artifacts on our public lands and on Indian tribal lands," said Carlie Christensen, a federal prosecutor. "We need to protect them, we need to treasure them and we hope this will discourage people."

Jeanne Redd's husband and Jerrica's father, James Redd, was also charged in the case. He committed suicide a day after the indictments were announced last month. Another suspect, 56-year-old Steven Shrader of Santa Fe, N.M., killed himself about a week later.

Artifact looting has been a common practice in the Four Corners area, which includes Utah, New Mexico, Colorado and Arizona.

Federal officials came under criticism after a series of raids and arrests in southern Utah on June 10, the day the indictments were unsealed. Local officials said federal agents were heavy-handed in those arrests. The FBI, BLM and U.S. Attorney General Eric Holder have defended their actions.

Christensen said the case is an ongoing investigation. She didn't rule out the possibility that additional people could be charged. Mother and daughter, who are from Blanding, Utah, are scheduled to be sentenced on Sept. 16