Summer brings warm weather, long days and family vacations—elements that add up to make it the busiest time of year in the national parks. That makes some folks shy away, but savvy photographers know plenty of opportunities still abound for making beautiful images in the most amazing of America’s wild places. To that end, we asked award-winning nature photographer and national parks expert QT Luong to recommend the best national parks for summer visits. He’s made more than 300 trips to the parks, and as the author of Treasured Lands—a 480-page compendium of photographs of the national parks that’s filled with useful information for his fellow photographers—Luong is uniquely qualified to highlight the best parks and special places within them to photograph...