The girlfriend of a man accused of leading a ring that smuggled methamphetamine and cash from California to Colorado in organic milk cartons pleaded guilty to one count of money laundering on Thursday.

Daniela Munguia De Ortiz, 34, is among 22 people arrested last May in metro-Denver, California, Iowa and Utah. Most of them have either pleaded guilty or reached an agreement with prosecutors to do so, said Jeff Dorschner, spokesman for the U.S. Attorney's office in Denver.

De Ortiz was a small fish in an operation that federal agents dubbed "Dark Angel." Agents seized more than six pounds of methamphetamine and $714,340 in cash and property in the bust and made arrests in metro-Denver, California, Iowa and Utah.

De Ortiz met Armando Mendoza-Haro, the alleged ring leader, in 2010 while she was living in California, according to her plea agreement, filed in U.S. District Court in Denver.

"Mendoza-Haro asked the defendant to open a bank account at Wells Fargo in California where she lived. Mendoza-Haro indicated that the account had to be at Wells Fargo, not Bank of America because Bank of America did not have branches in Colorado," according to the agreement.

De Ortiz arranged for a $7,000 deposit from Mendoza-Haro into the Wells Fargo account of a friend of hers. The friend then wrote a check for a similar amount to DeOrtiz, who deposited the money in her own account.

Mendoza-Haro told De Ortiz to then withdraw the cash from her account and give it to another woman, according to the agreement. "The friend then wrote a check to the defendant for $7,000 to help Mendoza-Haro conceal the true source and ownership of the original $7,000," according to the agreement.

De Ortiz faces a maximum sentence of up to 20 years and a fine as high as $500,000 for the money laundering count. But her agreement to cooperate could result in a sentence of from 18 to 24 months and a fine of no more than $40,000.

Mendoza-Haro is scheduled to plead guilty at 2:30 p.m. on March 7 before U.S. District Judge Philip Brimmer.

Mendoza-Haro and his sister, Reyna Mendoza-Haro were allegedly running the organization using a San Bernardino, Calif.-based company to move the drugs and cash to Colorado.

Tom McGhee: 303-954-1671, tmcghee@denverpost.com or twitter.com/dpmcghee