The recent uproar over armed EPA agents descending on a tiny Alaska mining town is shedding light on the fact that 40 federal agencies – including nearly a dozen typically not associated with law enforcement -- have armed divisions.

The agencies employ about 120,000 full-time officers authorized to carry guns and make arrests, according to a June 2012 Justice Department report.

Though most Americans know agents within the Drug Enforcement Agency and the Federal Bureau of Prisons carry guns, agencies such as the Library of Congress and Federal Reserve Board employing armed officers might come as a surprise.

The incident that sparked the renewed interest and concern occurred in late August when a team of armed federal and state officials descended on the tiny Alaska gold mining town of Chicken, Alaska.

The Environmental Protection Agency, whose armed agents in full body armor participated, acknowledged taking part in the Alaska Environmental Crimes Task Force investigation, which it said was conducted to look for possible violations of the Clean Water Act.

However, EPA officials denied the operation was a “raid” and didn't address speculation about whether it was connected to possible human and drug trafficking.

“Imagine coming up to your diggings, only to see agents swarming over it like ants, wearing full body armor, with jackets that say "POLICE" emblazoned on them, and all packing side arms,” gold miner C.R. Hammond told the Alaska Dispatch.

The other federal agencies participating in the operation were the U.S. Fish and Wildlife Service, the Bureau of Land Management, the Coast Guard, the National Oceanic and the Atmospheric Administration and the U.S. Park Service.

The Fish and Wildlife Service, Bureau of Land Management and Park Service are among 24 federal agencies employing more than 250 full-time armed officers with arrest authority, according the federal report, which is based on the 2008 Census of Federal Law Enforcement Officers.

The other 16 agencies have less than 250 officers and include NOAA as well as the Library of Congress, the Federal Reserve Board and the National Institutes of Health.

The number of federal department with armed personnel climbs to 73 when adding in the 33 offices of inspector general, the government watchdogs for agencies as large as the Postal Service to the Government Printing Office, whose IG has only five full-time officers.

The EPA defended its use of armed officers, after the Alaska incident.

"Environmental law enforcement, like other forms of law enforcement, always involves the potential for physical, even armed, confrontation," the agency said.

But Alaska Gov. Sean Parnell has already ordered an investigation, saying "This level of intrusion and intimidation of Alaskans is absolutely unacceptable."

In addition, Alaska Sens. Lisa Murkowski, Republican, and Mark Begich, Democrat, have inquired about the incident.

Murkowski said purported concerns about rampant drug and human trafficking in the area sounded “wholly concocted” to her.

“This seems to have been a heavy-handed and heavy-armor approach. Why was it so confrontational? The EPA really didn’t have any good answers for this,” she told the newspaper.

This is not the first time armed EPA guards have been accused of intimidating behavior.

In May 2012, North Carolina resident Larry Keller was visited by armed EPA agents after sending an email to Al Armendariz, the regional administrator who was video-taped saying his enforcement strategy was to "crucify" executives from big oil and gas companies.

"The charter of the EPA is to protect the environment and public, not to act as a quasi federal police department," Keller said after the brief but tense exchange with agents about whether the missive might seem suspicious.

The Department of Homeland Security employs nearly half of all federal officers, through Customs and Border Protection and Immigrations and Customs Enforcement, the most recent statistics show. The statistics also show the number of CBP officers increased by 33 percent from 2004 to 2008. The number for ICE was 20 percent over the same period.

Meanwhile, the four largest Interior Department agencies employed fewer officers during that time, including the Park Police, which employed 547 officers in 2008, 11 percent less than four years earlier, according to the 2012 report.