About a dozen marijuana fields, some of which were under surveillance for months, have been found in a belt stretching almost 150 miles. Tens of thousands of plants have been seized or destroyed -- many as they were just entering maturity, said Drug Enforcement Administration Supervisory Special Agent Michael Root.

"We've just never really seen this in Utah before," Root said.

At least 10 people have been arrested in connection with the fields. One of them, Ignacio Rodriguez, is accused of supplying food, fertilizer and other goods to people monitoring the fields.

Rodriguez was also the person who unwittingly showed them where the fields were located, Root said.

Police on Thursday and Friday announced the discovery of three more fields.

One was found on Mount Dutton in Garfield County. Beck Bronson, a spokeswoman for the county, said law enforcement raided the farm about 5:30 a.m. Friday. Police were still removing 1,800 marijuana plants that afternoon.

Another field was found in an area known as Little Creek in northeast Iron County. The field had 3,000 to 5,000 plants and was a "sophisticated" operation, said Iron County Sheriff Mark Gower.

Another marijuana field was located in Sevier County contained 18,000 plants, police said. Nate Curtis, a detective with the Sevier County Sheriff's Office, said the field was found on White Mountain in Salina Canyon.

The raids trace their origin to the discovery of a field last autumn. Root said rather than swoop in and destroy it, federal and local agents put it under surveillance. Eventually, Root said, they spotted Rodriguez.

Root said agents followed Rodriguez as he delivered to the fields, taking supplies to the men and women assigned to cultivate the huge swaths of marijuana plants spread across southern Utah. Root said the growers appear to have been recruited in Mexico, smuggled into the United States, then assigned to tend and live in a field for three months at a time.

"One guy said he was going to make 1,500 bucks for the whole summer and they helped pay for some of this expenses to get across the border," Root said.

The organization operating the fields is based in California, Root said, and apparently was trying to grow in Utah rather than try to smuggle Mexican marijuana into the United States. Rodriguez is a lieutenant in the organization, Root said.

Root said the DEA had planned to continue their surveillance on the Utah fields, at least for another week. But when a hunter recently found a field in Shurtz Canyon south of Cedar City and began telling people about it, the DEA was forced to bust the fields ahead of thier schedule.

But catching the cultivators has been difficult. Root said some of the suspects have fled into the thick brush and rugged southern Utah terrain.

Men and women may still be hiding or wandering in the wilderness, Root said. Root said agents arrived at one field and saw a man run away barefoot.

At another field, no suspects were found, but a stove was still running.

"They've been living up there for 60 to 90 days. They know all the ins and outs," Root said.

Police advised people living, hiking or traveling through rural southern Utah to watch for people who appear out of place or signs of more marijuana fields. Root said one tell-tale sign of the fields are black hoses or pipes connected to remote water sources that are used to irrigate the plants.

Five people were arrested in Iron County in connection with the fields, Gower said. Rodriguez was being held on a federal warrant accusing him of being an undocumented immigrant possessing a firearm. Another man arrested in the sweeps remained in the Iron County jail on suspicion of forgery.

Three others posted bail after being arrested on suspicion of misdemeanor drug crimes. Root said they were found at Rodriguez's home in Iron County and not in the fields.

Five people were arrested and booked into the Sevier County jail after the bust in Salina Canyon.

- Mark Havnes contributed to this report.

ncarlisle@sltrib.com