BOISE (AP) — A law lowering from 21 to 18 the age limit for carrying a concealed handgun within city limits in Idaho without a permit or training went into effect Monday.

The law passed by Idaho lawmakers and signed by Republican Gov. Brad Little aligns gun laws in urban areas with rural areas where those 18 and older can already carry a concealed handgun. About a half dozen other states have similar laws allowing 18-year-olds to carry concealed guns without a permit.

That’s one of more than 300 new or amended laws passed by Idaho lawmakers earlier this year.

Backers of the new gun law said the change will protect law-abiding citizens from accidentally breaking the law when they travel across a county and enter city limits.

Opponents said there’s a big difference between rural Idaho and urban Idaho and not allowing persons age 18 to 20 to carry a concealed handgun in urban areas is reasonable to prevent accidental shootings and shootings resulting from altercations.

Another new law requires motorists to slow down and move over when approaching tow trucks and maintenance vehicles parked along roadways with lights flashing.

Lawmakers also increased fines for motorists unlawfully passing a loading or unloading school bus. A first-time offense went from $100 to $200, with fines escalating from there.

Another new law requires public libraries to filter access on their internet servers so that obscene and pornographic material can’t be accessed. The estimated cost is up to $2,500 per library, but possibly much less depending on the type of system.

Lawmakers also approved broadening the definition of abuse involving child victims sustaining head injuries.

The change removes the term “subdural hematoma” to determine abuse and replaces it with head and brain injuries. A subdural hematoma is defined as blood collecting outside the brain. Backers say using broader wording is consistent with other descriptions of injuries involving child victims.

In another change to Idaho law, bounty hunters must now wear badges and notify county sheriffs of their intentions before attempting to apprehend someone. The new law also requires that bounty hunters be 18 or older, be a citizen or legal resident of the United States, not be mentally ill as defined in Idaho law, and not be a fugitive from justice.

Backers said the legislation is needed following several incidents involving bounty hunters who opened fire and on at least one occasion put at risk an innocent person.

The laws will also apply to bounty hunters from other states entering Idaho.

The state’s nearly 50-year-old mining laws also received an update that was backed by the Idaho Mining Association.

Backers said the update was needed to protect the viability of Idaho mining from federal litigation, federal regulation and those opposed to mining.

Those opposed said financial mechanisms intended to make sure companies pay for the cleanup costs of abandoned mines could leave Idaho taxpayers with cleanup bills if a company declares bankruptcy.

A state board that pays a federal agency to kill wolves that attack livestock and elk, and that would have ended without lawmaker action, was extended indefinitely and remains in effect.

Several news conferences also took place on Monday involving new statutes or designations from this year’s Legislature.

Little dedicated U.S. Highway 20 as the Idaho Medal of Honor Highway. Idaho’s portion of the highway is part of a larger plan to have the entire highway that begins in Newport, Oregon, and ends in Boston receive the designation.

Meanwhile, Democratic Rep. Melissa Wintrow and former Democratic Rep. Hy Kloc got the first “pet-friendly” license plates. Money from license plates will go to pay for spaying or neutering pets owned by low-income families.