Hunting rules for the parks will not change because of this law. Currently, hunting is allowed in cordoned-off locations in 42 parks, but only after the peak tourist season.
Barna said visitors do need to be aware of the changes in laws across state lines within the parks. For instance, Yellowstone crosses into Wyoming, Montana and Idaho, which all have differing gun laws.
While some visitors might be apprehensive to visit the parks now, Barna pointed out that others who have stayed away because of the gun restrictions might now be more willing to visit.
Arulanandam said the NRA lobbied for the change for seven or eight years. The measure gained momentum after 2008 when the Supreme Court struck down a handgun ban in Washington, D.C., and declared that individuals have a constitutional right to possess firearms for self-defense and other purposes.
The national park gun law change was included in an amendment to the Credit Cardholders' Bill of Rights Act of 2009, authored by Senator Tom Coburn, R-Okla., and signed into law by President Obama on May 22, 2009.
"We think wherever Teddy Roosevelt is, he's got to be rolling his eyes and shaking his head, said Peter Hamm, communications director of the Brady Campaign to Prevent Gun Violence. "The national parks are places of solitude and quiet and places to get away from the large number of firearms they are already seeing in society."
The Brady Campaign sued the government to block the rules change. The courts initially sided with the Brady campaign before Congress passed a law overturning that decision.