All of the nation's national parks will allow visitors in for free on three weekends this summer as a way to encourage affordable vacations and boost the economy.

In Utah, that means the famous Grand Circle of Zion, Bryce Canyon, Arches, Canyonlands and Capitol Reef national parks will waive admission fees of $3 to $25 during the weekends of June 20-21, July 18-19 and Aug. 15-16.

Interior Secretary Ken Salazar announced the freebies Tuesday during a news conference in Ohio's Cuyahoga Valley Park.

"During these tough economic times, our national parks provide opportunities for affordable vacations for families," he said. "National parks also serve as powerful economic engines for local communities, and we hope that promoting visitation will give a small shot in the arm to businesses in the area."

Most Americans, he added, live less than a day's drive from a national park.

The Obama administration has handed out millions in economic stimulus funds for the national park system. Dinosaur National Monument on the Utah-Colorado line near Vernal snagged $13.1 million to rebuild its world-renown quarry exhibit.

The monument also will receive $628,000 to replace water lines, repair trails, rehabilitate the Gates of Lodore boat ramp on the Green River and install energy-efficient windows at the park's headquarters in Colorado.

Zion National Park is getting nearly $1 million for solar-energy panels and trail maintenance. In Bryce Canyon, $579,000 will go to new restrooms and repairs to the one-mile Bristlecone Trail.

There are 391 national parks in 49 states, with Delaware the only exception. The waiver will affect the 147 national parks, preserves, monuments, heritage sites, trail and river areas that charge entry fees.

Nationwide, parks last year attracted more than 275 million recreation visits. Spending by non-local visitors provided $10.6 billion for local economies, supporting more than 213,000 jobs, not counting Park Service jobs, Salazar said.