AUGUSTA – All-terrain vehicle operators who trespass or drive recklessly face tougher penalties under a new law that fine-tunes major ATV regulations enacted two years ago.

“The number of ATV users continues to grow, and we’re still learning how to best regulate the riders,” spokesman Mark Latti of the state Inland Fisheries and Wildlife Department said Monday.

In 1994, Maine had 23,000 registered ATVs, but the number had nearly tripled to 66,000 a decade later. With the proliferation of trail users, the Legislature in 2004 passed a major law that raised registration fees and set limits on where and when ATVs can be used.

Under state law, licenses and permits issued by the department for operating an ATV on temporarily closed trails or on private property without permission can be suspended. The new law says suspensions must last for at least 90 days.

The new law, signed May 4 by Gov. John Baldacci, also includes some mandatory penalties.

It says the game department must suspend for at least a year all fish and game licenses, permits and registrations for ATV violations that involve property damage, operating under the influence if the driver is under 21 years of age, operating an ATV recklessly or to endanger, or failing to stop for an officer.

The law extends the maximum distances an ATV can travel on a public road in order to cross from 300 to 500 yards.

The law creates four part-time positions in the Department of Conservation to help with ATV club and trail development and landowner communications.

The legislation was submitted by the ATV Trail Advisory Council, whose participants include ATV users, landowners, municipal and state officials and environmental group members.