We spent 2 days with Carl; the first day started at the top of Rocky Mountain National Park and ended at the bottom. The 2nd day was in the foothills. I have never had a birding guide that worked as hard as Carl, from giving advice on finding birds the days before and after our 2 days with him, to sticking to it when searching for the particularly difficult to find birds. Our goal was the White-tailed Ptarmigan and the American Dipper. We got great looks at both, plus 7 other life birds. My wife and I both highly recommend Colorado Birding Adventures.