The Colorado River will be rocking and rolling through Grand Canyon National Park later this month as a "spring disturbance flow" is released from Glen Canyon Dam upstream.

There have been, and continue to be, women who played key roles in establishing national parks or who are honored by parks that bear their name or were influenced by their work, or had positions with the National Park Service. How many do you know?

The National Park System is full of superlatives: the biggest, the smallest, the longest, the deepest, the rarest, the tallest, and on and on. National Parks Quiz and Trivia #26 takes a look at some of these superlatives while testing your knowledge and teaching you a little something you might not have known.

Agriculture-generated emissions of ammonia and nitrogen are a problem at Rocky Mountain National Park in Colorado, though researchers at Texas A&M University believe they can help reduce them by working with livestock operations along the state's Front Range.