I'm not sure if it was the time of year, conditions, or all combination of both but
the Rocky Mountain National Park is the best place I have ever fished.
I've never fished a location that was so prolific with trout. They weren't stupid you had to properly drift your fly but if you even had the slight resemblance of a good drift it usually resulted in a strike. Any buggy high floating pattern is all you needed. I fished mainly with caddis and a royal wulff.
One of the biggest fish I had the pleasure of seeing and the heartbreak of losing was to a Chernobyl Ant. The only one I had with me. I had the fish deny several other flies and then finally come up and take the Chernobyl Ant. As soon as I set the hook I felt resistance then that sickening slack from your knot popping. It was my fault not tying the knot properly and it was cool to just see a fish eat like that but I can't help but wonder what if.
The lakes weren't as bad as the creeks but they were still chilly. The pic above is from Sprague Lake. I was the only one wading in the water.
Other people were fishing with spinning rods from shore I didn't see anyone catch anything but there was a big fish jumping right out of casting distance. I'm pretty sure it was a cutthroat. That is my one regret is not trying to target some of the different trout species that live in the Rockies. When I first read a book about the area I thought the locations were too far to really target. I checked the book again later and realized many of the places I would have liked to target I was either right next to or easily with in driving distance.
There's a bus system that takes you to various locations in the park, one option I didn't try but think would be a good idea is to park at one of the low altitude bus stops. The idea is to have the bus take you to all the stops going up towards Bear Lake. You could fish for as long as you wanted at each stop and take the bus when you wanted to go to the next area. That would be a great way to spend the day.