National Park Week runs from April 15 to 23 and to celebrate, the National Park Service is giving you the chance to venture into the nation's parks on the weekends free of charge.

On April 15 and 16 and again on April 22 and 23 you can visit parks for free.

Washington is home to 15 national parks, four of which usually charge an entrance fee.

Here's the now-entrance-fee-waived Washington state parks for the upcoming weekends:

- Fort Vancouver National Historic Site
- Lewis & Clark National Historical Park
- Mount Rainier National Park
- Olympic National Park

If you’re up for a road trip, Oregon is waiving admission to Crater Lake National Park and the Lewis & Clark Historical Center.

Can't decide which one to visit? The NPS has a tool that can match activities with the best national park.