GLENWOOD SPRINGS, Colo. (AP) _ An 8-month-old baby girl died from drinking milk poisoned with raw sewage, and her mother has been charged with criminally negligent homicide.

The filthy conditions in the family's trailer spurred investigators to examine milk fed to Samantha Alena, who died just after Christmas from methemoglobinemia. The infection oxidizes hemoglobin, rendering it unable to transport oxygen in the blood, an autopsy said.

Authorities didn't charge her mother, Markele Peck, 25, until Wednesday because investigators first thought the baby died of Sudden Infant Death Syndrome. After the autopsy, prosecutors took months to rule out other possibilities that could have produced the little-seen infection.

Officer Brett L. Williams said he saw dried fecal matter all the way to the top of the bathtub.

``There was trash everywhere,'' emergency medical technician Suzy Taylor wrote in her report. ``The smell and the stench was overwhelming.''

The baby's bottle appeared unclear, officers said. The autopsy found deposits of the spoiled milk in the infant's stomach.

``If this child was in a caring home ... it would probably still be alive,'' coroner Dr. Rob Kurtzman told police.

Mrs. Peck, who now lives in Rifle, was released on $10,000 bond. Her 2-year-old boy remains in her care.

John Peck, the baby's father who was not charged in the case, told authorities his children hadn't been to the doctor since they were 2 months old. He said he had little to do with their care.