On August 25th, in honor of the National Parks Birthday you can free admission to National Parks across the country. This promotion is offered periodically throughout the year. Other upcoming days will be on September 30 for National Public Lands Day and November 11-12 to honor Veterans Day.
Here is a list of participating Utah parks:
Arches National Park
Bryce Canyon National Park
Canyonlands National Park
Capitol Reef National Park
Cedar Breaks National Monument
Dinosaur National Monument
Glen Canyon National Recreation Area
Golden Spike National Historic Site
Natural Bridges National Monument
Zion National Park
Go here to see ALL national parks participating.