Interior Secretary Ken Salazar said in a release a visit to a national park would be a good New Year's resolution.
"Many people have made resolutions to spend more quality time with loved ones and to get outdoors and unplug in 2011," Salazar said. "There's no better place than a national park to help keep those resolutions. Parks offer superb recreational opportunities, making them perfect places to enjoy our beautiful land, history and culture, and nurture a healthy lifestyle.
"In these tough economic times, our fee-free days will give families many opportunities to enjoy our nation's heritage and natural beauty in meaningful and affordable ways."
The 2011 fee-free dates will be the weekend of Martin Luther King Jr. Day (Jan. 15-17), National Park Week (April 16-24), the first day of summer (June 21), National Public Lands Day (Sept. 24) and the weekend of Veterans Day (Nov. 11-13), the park service said.
Many national park concessions will also offer discounts on fee-free days, saving visitors money on food, lodging, tours and souvenirs, the service said.