MODESTO (AP) — State and federal authorities took down a large drug-trafficking operation in the Northern San JoaquinValley with links to Mexico, arresting 11 people and seizing drugs and weapons, officials said.

The arrests on Wednesday followed a yearlong investigation that included confidential informants, aerial surveillance and wiretaps, according to a news release from the U.S. Immigration and Customs Enforcement’s Homeland Security Investigations branch and a search-warrant affidavit.

The Modesto-area narcotics ring was allegedly trafficking large quantities of methamphetamine and marijuana. As part of the operation, investigators conducted searches at more than two dozen locations in the valley, including two ranches in Stanislaus County, Homeland Security Investigations said in the release.

Authorities seized a shotgun, two handguns, nearly 60 pounds of processed marijuana and more than $20,000 in cash, according to the release. They also came across seven indoor marijuana-growing operations.

The investigation began in early 2013 after a confidential informant told agents with the California Department of Justice that he had delivered methamphetamine to two horse ranches in Patterson, according to the affidavit filed in U.S. District Court for the Eastern District of California.

That informant and another informant then arranged meetings and phone conversations with the suspects during which they discussed purchasing methamphetamine, marijuana and weapons and transporting methamphetamine. The informants bought drugs and weapons as part of the investigation.

One of the suspects named in the affidavit, Francisco Felix, who was identified as the head of the operation by other suspects, told an informant during a meeting in September that he had access to 200 pounds of crystal methamphetamine in Mexico, according to the affidavit.

Investigators say the drug ring used sophisticated methods to conceal and smuggle the drugs, including commercial trucks with hollowed out drive shafts and vehicles equipped with hidden compartments.

Six of the suspects who were arrested are facing federal charges. Five others are expected to be charged in state court, according to the news release.

Felix was among those arrested, said Immigration and Customs Enforcement spokeswoman Virginia Kice. He was scheduled to appear in court on Thursday afternoon. She did not know whether he had an attorney.