The fee-free designation applies to entrance fees only and does not affect fees for camping, reservations, tours or use of concessions.
Other National Park Service units in Washington that are waiving their entrance fees this weekend are Fort Vancouver National Historic Site, Lewis & Clark National Historical Park and Whitman Mission National Historic Site.
In addition to the Park Service, the U.S. Fish and Wildlife and U.S. Forest Service also are honoring the free entrance weekend.
The free weekend is the first of several fee free days the National Park Service has planned throughout 2012. The other dates are April 21-29 (National Parks Week), June 9 (Get Outdoors Day), Sept. 29 (National Public Lands Day) and Nov. 10-12 (Veterans Day weekend.)

