The truly great fishing was in the late 70s. There was a reasonable (not excessive) amount of trout stocked and plenty of food in the river. Fishing pressure was light. When I went fishing, launching at Lees Ferry, I only saw a few other boats on the river. We usually caught a dozen fish each - all in the 3-10 pound range.
Fishing changed in the 80s. The great fishery was highlighted in National Geographic Magazine. When I went fishing in the 80s the number of anglers was 10 times greater. I liked to drift down a current and fish on the side where the current turned and ran upstream. I fished right on that current boundary and caught fish every time. After boating pressure increased I would drift down my little spot and then would have to wait for a dozen boats to go passed before I could take another run at my spot.
At the same time the river vegetation changed from the one that the fish really liked to another that was not as productive. I have forgotten the names of the vegetation after all these years. I quit fishing the river in the 80s because I got distracted by the huge adult stripers that were swimming in Wahweap Bay.