There have been Grannoms in lower Spring Creek, Bellefonte to mouth, at least since the late 1980s. I know that from direct experience. Whether they were there before that, I don't know.
And they were pretty heavy in those days, too. That was long before the dam removals.
Insects fly, so dams do not limit their range, because they can easily fly right past them.
There are a few Grannoms in Spring Creek from Bellefonte on upstream. I saw a couple at Fishermans Paradise this evening. But by a couple I mean literally two. I've never seen significant numbers above Bellefonte.
Greg Hoover told me several years ago that he found grannom larvae as far up as Rock Road (above Benner Springs), but not in large numbers.
The main reason there are far more Grannoms below Bellefonte than above, IMHO, is the large volume of spring water coming in from Logan Branch and the Big Spring.
Someone told me on Saturday that the Grannoms were on in lower Spring Creek. I fished it Sunday and the hatch was good. A friend of mine fished it today and said the hatch was very sparse today.
Since they've started here, they're probably starting on other streams, too. Or will be very, very soon.
OK, now yinz can tell us where Grannoms, or other good hatches, are hatching in the southern half of the state.