Back in the early 1990s when I was a fishing guide working for the Yellowstone Angler I spent 20 to 25 days a year walk/wade guiding on the spring creeks. The rest of the year was Yellowstone Park, Sixteen Mile Creek and boat trips on the Yellowstone River.
In those days in mid-summer the Pale Morning Dun hatches were thick and everybody wanted on the creeks. If you wanted to fish at DePuy's O'Hairs or Nelson's Spring Creek your best hope was booking a day at least a year in advance, because this year was already filled up.
That was 25 years ago. Now there are twice as many outfitters and three times as many fly fishermen. And the Spring Creeks are not filled up. I was there today and the upper creek at O'Hairs was empty. I wasn't fishing. I was collecting mayflies for a closeup photography session. But I have a hunch I could call and get a rod tomorrow. Not that I would. The rod fee is too high for for me at $125 dollars, or what ever it is. And the hatches aren't as thick anymore. I had a hard time collecting a dozen duns to photograph.
Perhaps the creeping lack of mayflies has a lot to do with it. The fishing there is still good. But not as good as it used to be. But I think it's more than that. The old guard is dying off and the new guys aren't buying into the Spring Creek mystique anymore. There are more fishermen statewide and nationally. By a lot. And Spring Creeks only half full on most days. Something interesting is going on.
Why are the mayflies in decline? Nobody knows the answer to that question. Herbicices? Global Warming? Space Aliens? Mud Snails? Nobody knows and nobody who makes money from the fishing industry wants to talk about it. The Yellowstone River is doing fine. A bit more crowded than it was but still fishing well. The Spring Creeks, on the other hand, are not. Not what they used to be anyway.
The following is DePuy's an hour after sunrise. Jan 1st 2000. The morning all the computers were supposed to crash and die.