Even without an expensive North Face backpack, you should absolutely visit America's majestic national parks. And there's no better time to tick that excursion off the bucket list than next week when every national park is offering free admission.
April 16 - 24, 2016 is National Park Week, a week established by presidential proclamation when all national parks waive admission fees. Yes, some national parks are always free, but the really popular ones--the Grand Canyon, for examplenormally charge admission. This is your chance to get in all the parks, while spending absolutely nothing.
Now the only thing you have to do is decide which parks you're going to hit. But to make that tough decision a little easier, here's an official ranking for you. If distance is a factor (since this is pretty late notice), you can go to "find my park" to discover the park closest to you. For more info, check out the National Park Service website.