CHEYENNE - Two more alleged members of a methamphetamine ring in Natrona County pleaded guilty to federal drug conspiracy charges Monday in U.S. District Court in Cheyenne.

Griselda Cortes-Nieto, 36, and Ana Antano-Villegas, 26, had pleaded not guilty to meth-related charges in March.

After the women, both Mexican nationals, changed their pleas Monday, Judge Clarence Brimmer ordered them held without bond. He said if they were released on bond, U.S. immigration officials would arrest them and have them deported.

Federal prosecutor Randall Carnahan said the government has no plea agreement with Cortes-Nieto. The guilty plea exposes her to a mandatory minimum sentence of 10 years to life in prison, plus a $4 million fine and five years of supervised probation.

She said under oath and through an interpreter that she did the accounting for the meth sales and knew what was going on. She said she was not involved in wiring money from the sales to California.

Asked if she ever used meth, Cortes-Nieto answered through an interpreter, "No. Never."

Antano-Villegas had a plea agreement that allowed her to plead guilty to two lesser included offenses and to be incarcerated in the United States near her family. She faces five to 60 years in prison on the two counts, in addition to $3 million in fines and supervised probation on her release.

She admitted she sold meth from her residence in Evansville.

According to earlier testimony by a special agent with the Wyoming Division of Criminal Investigation, a confidential informant in mid-January gave Antano-Villegas $1,000 in exchange for three plastic bags containing a substance that later tested positive for methamphetamine.

Antano-Villegas admitted Monday that she sold the three baggies but said the buyer did not pay her for it.

Brimmer told the two women, who appeared separately, that a presentence investigation will take eight to 10 weeks.

Earlier in June, two other Mexican national defendants in the conspiracy case changed their pleas to guilty.

Pablo Sergio Martinez-Najera, 21, and his wife, Lucy Adriana Agustin-Salgado, 24, were arrested in February when agents seized more than $350,000 worth of meth and nearly $42,000 in cash from two trailer homes in Mills.

Martinez-Najera pleaded guilty to five federal counts of distributing meth, and a single conspiracy charge. He also was linked to a gun found during the raid.

His wife, Lucy Agustin-Salgado, admitted under oath that she packaged and sold 84 grams of methamphetamine. She also admitted that she traveled to California and Montana as part of the meth ring, and conspired to sell the drug.

The four defendants who have pleaded guilty are among six people arrested by authorities in February and who are named in a federal grand jury indictment handed down in March.

Contact Joan Barron by e-mail at joan.barron@trib.com or by phone at (307) 632-1244.