The mosquitoes pull out all the stops to welcome us as we arrive alongside Hog Island in a fisheries patrol-style boat and take turns donning hip waders to make our way through the ocean lagoon to the rocky shore. We’re the only humans around and as we take a rare tour of this densely forested island, the overly abundant resident mosquito population follows and feasts.

At the end of their very long days on the fire lines battling the Washburn Fire at Yosemite National Park, firefighters retreat to the fire camp where they can eat, sometimes shower, and rest for the next day. Understandably, with more than 1,000 firefighters at work, these camps can generate a great deal of waste. And that's where a recycling program undertaken by the U.S. Forest Service is making a big impact.

Though the Washburn Fire continues to burn and grow in size at Yosemite National Park, the Mariposa Grove of Giant Sequoias seems to have avoided the flames thanks to on-the-ground operations to protect the trees.

It’s time to test those national park mental muscles with Quiz and Trivia #51. Find out how much you really know about units within the National Park System.