The last time I was in Yellowstone, I found myself not so concerned with using wide angle lenses, but rather shooting at about 70mm and stitching a series of shots together to make panoramic landscapes. When I wasn't shooting for panos, my 28-70mm on a full frame sensor, was just fine for single frame landscapes. On the other end of the spectrum, I was photographing wildlife with a 200-400mm 1.4x teleconverter.