Some of the six people arrested in the alleged plot to kill soldiers at Fort Dix are supposed to have practiced their shooting at a public target range in Monroe County.

It is one 29 little-known firing ranges across Pennsylvania that are open to anyone. There are no on-site attendants. Users are typically hunters testing their firearms.

"This is the first we have heard of any terrorist-type use of a public range," said Jerry Feaser, press secretary for the Pennsylvania Game Commission, which oversees the ranges.

Each has wooden shooting positions and is surrounded on three sides by an earthen berm that serves as backstop for the bullets, Feaser said.

Assault-style weapons are not permitted on the ranges unless they have been permanently modified to fire only a single shot with each trigger pull. Semiautomatic weapons can have only three rounds in the magazine for a rifle, and six rounds for a handgun. No armor-piercing bullets, or incendiary, explosive or tracer ammunition are allowed, Feaser said.

State police said they have not received reports of gangs or other problems at the public shooting ranges.

The Monroe County range is in a corner of an 18,800-acre preserve, some of which was acquired from the U.S. government in 1949, and had previously been used by the Army and National Guard as an artillery range for antiaircraft and antitank rounds.

Public shooting ranges are not uncommon. The New Jersey Department of Environmental Protection Web site lists 12 "hunter training areas" for shotguns, bows and arrows, or muzzle loaders. They do not permit handguns.

In Ohio, there are 20 public shooting and archery ranges.

Contact staff writer Mari A. Schaefer at 610-892-9149 or mschaefer@phillynews.com.