I left Seattle in the evening on June 24th with a friend who had flown down from Alaska to join me on a Montana trip, and we drove late into the night to camp along the NF CDA and be ready to fish in the morning as a break in the long drive to Montana. We didn't get to sleep until around 2am, but we still got up fairly early (for me, that's 8am) and hit the water. We fished through a few good pools before any fish stirred, and the action gradually heated up throughout the morning. The campground host later laughed at our early start and verified that it's generally not worth being out there until the sun heats the water at that time of year.
No really big fish showed themselves, but there was fine action on small to mid-sized Westslope Cutthroat, and it was only getting better when we had to tear ourselves away from the water at 2pm to complete the long drive to Yellowstone.