WINDOW ROCK, Ariz. — Isabel Whitehair had never heard of methamphetamine before her 2-year-old son reached under the sink at bath time, pulled out a pipe and put it to his mouth.

"This is Daddy's," the boy told the Navajo woman. "Dad said it's lucky medicine."

A year after the nation's largest Indian reservation launched an attack on meth — raising penalties, increasing training for police and developing an interagency task force — the illegal and highly addictive drug is still very much a scourge of the Navajo Nation.

No statistics are kept on meth-related crime on the reservation. But cases like Whitehair's — and that of an 81-year-old woman arrested last month on charges of dealing meth — make it clear the problem has not gone away.

Lynette Willie, a spokeswoman for the Navajo Department of Behavioral Health Services, calls the drug "a modern-day enemy to the Navajo people."

"I've seen what it's done already," said Navajo President Joe Shirley Jr. in a recent interview. "It's awful. It's horrible."

Police say there have been signs for several years of growing meth use on the reservation: more paranoia among people stopped for traffic violations, more meth paraphernalia littering the landscape, and tragic cases of meth-related violence and neglect.

In 2004, a father was accused of leaving his 18-month-old son alone on a hilltop. The man said he forgot about the child because he was high on meth. Police found the child dead. In 2005, authorities say, a man choked to death his 36-year-old wife. Investigators said the two had been smoking meth and drinking beer.

Police say meth has become a bigger law-enforcement problem on the 300,000-member reservation than even alcohol, which has been devastating to Indians. Window Rock Sgt. Wallace Billie said the number of meth-related calls the department receives has surpassed those involving alcohol.

Last year, tribal lawmakers took action, criminalizing meth for the first time. Possession or sale of meth on the Navajo Nation is now punishable by up to a year in jail and a $5,000 fine. (Meth possession is already a federal offense, but federal authorities venture onto the reservation only in serious cases.)

There is no word in the Navajo language for methamphetamine; the closest is one that means "eating your body." Whitehair, who no longer lives with the boy's father, has her own term: "the devil's drug."

"It takes your conscience away," she said. "It takes away your ability to know right from wrong."

Virgil Teller, a 35-year-old Fort Defiance resident, used the drug so often that his face and throat were chemically burned. Meth kept him up for days at a time, during which he sometimes went without eating.

"Once you start on it, you don't want to stop. Even though it hurts you, you still do it," said Teller, who has been clean for five months.

Law enforcement officials believe the meth is coming from Phoenix and Mexico, and say it is particularly hard to stop on the huge reservation, which covers 27,000 square miles in Arizona, New Mexico and Utah and is plagued by a shortage of police officers.

FBI agents cannot blend in on the reservation the way they do in the big city. Also, communities can be separated by hundreds of miles and there is only one road to most homes, which mean officers can usually be spotted well before they arrive.

"Most residents have fences, dogs or live out in the middle of nowhere," said Window Rock Police Officer Gilbert Yazzie. "So if you start driving in that area, people they are affiliated with will tell them there is an officer in the area."

The reservation's six jails have a total of only about 70 beds. Meth violators often are kicked out after 8 to 12 hours to make way for more serious offenders, said Samson Cowboy, director of the Navajo Division of Public Safety.

There also is no drug rehab center on the reservation; the Navajos contract instead with cities on its borders. But a 72-bed, $10.2 million treatment center has been proposed for the reservation.

Willie said the Navajo Nation needs to know what it is up against: a powerful drug that is disrupting Navajo families on the reservation, a place already beset by grinding poverty and nearly 40 percent unemployment.

"We should be protecting the sacredness of human life, and that's the bottom line," she said. "This is about human life."