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Free admission offered to all national parks

Spring runoff is in full swing as seen from a distance of Bridalveil Falls on Friday, May 16, 2008 in Yosemite National Park, Calif. (Gary Kazanjian)

April 20, 2012 12:00:00 AM PDT
This weekend may be the best time to take a trip to one of the great national parks in California or across the country.

The U.S. National Park Service is offering free admission to all national parks in celebration of National Park Week from Saturday, April 21 until Sunday, April 29.

All of the nearly 400 parks, preserves, monuments, recreation areas and historic sites in the system will be free of charge.

While you're there, the Park Service wants you to snap a photo of yourself and post it to their website.

Every U.S. state except Delaware has at least one national park. There are as many as 25 of these sites available throughout California.