Trip Report: Spring Creek, Centre County, PA – Date Fished May 12, 2009

The Sulphurs are Here!

I’m sure we all have a favorite hatch – for me it’s the Sulphur Hatch on Spring Creek.   There are several reasons for this: first nostalgia and second the fact that it is a great hatch on a great stream.  The nostalgia comes from my time at Penn State.  Spring Creek is where I learned to Fly Fish and the Sulphur hatch was the first good mayfly hatch that I ever fished successfully.

If it was only nostalgia though it wouldn’t be of much interest to others – so be assured it is a great hatch to experience on one of Pennsylvania’s most productive wild trout streams.

On this particular day we arrived at the creek around 10:30 AM.  The air temps were in the high 50’s to low 60’s through out the day, and the sun was shining.  The stream was in perfect condition, with a nice  full spring flow – but not to high.

E.dorothea (left) and E. invaria (right) I think!? It can be hard to say sometimes.

With the hope of finding hatching sulphurs we headed upstream looking for good “Invaria” water.  The early season “Sulphurs” on Spring Creek are  Ephemerella Invaria – (Ephemerella Rotunda and Ephemerella Invaria have recently been grouped as one species, Ephemerella Invaria).  Invaria nymphs prefer fast moving currents and prior to emergence may seek pockets of slower water adjacent to the fast water.

I snapped the picture at the left hoping to get a good record of the coloration of Spring Creek’s sulphur nymphs. The two nymphs that I found are clearly different – the slightly darker nymph on the left was definitely smaller than the other one. So I’m saying that is the dorothea – although I’m not willing to bet on it. However, regardless of a positive identification – you could tie some nymphs to match the picture and be all set.

After a short walk we found what looked liked a perfect stretch of riffles and runs, with plenty of instream rocks and pockets – perfect water to look for the invaria hatch.

Well it wasn’t long before it started. Beautiful little invaria duns began to emerge sporadically – and all around us the fish were taking the duns from the surface.  I’d estimate the best hook size to imitate the duns was a size 16 – but a sparsely dressed 16. These particular inavaria duns have quite a bit of orange to them – on other streams they can be much more pale-yellow. It was pretty clear that the fish were taking the fully emerged duns from the surface.  They may have been taking emergers too – but I never really had much success with any emerger patterns.  That wasn’t a problem though because I was taking fish consistently on top with dries.  This surprised me a bit – in the past I’ve caught many more fish on the emerger. Perhaps this was due to timing – maybe since it was early in the emergence period, the fish hadn’t been fished so hard yet, and hadn’t seen every possible Sulphur dry-fly pattern created. I’ll never know why – but I guess that is what makes fly-fishing so challenging. It seems to never happen the same way twice. The hatch was consistent – but not blizzard like – all day.  There was a brief increased flurry of sulphurs during the warmest part of the day at approx. 3:00 PM.

Hair-Wing Thorax Sulphur

I managed to catch fish on a variety of different patterns but one style seemd to be particularly effective: The Hair-Wing Thorax Sulphur. I tied some of these up after reading Swisher and Richards’ Selective Trout. They mention that flies tied with a single clump deer-hair wing were more effective than the fan-wing Comparadun style flies. However, the clump wing flies often landed on their side. To combat this tendency I added a sparse thorax-style hackle (clipped on the bottom). Well the fish seemed to like it – at least on this day.

Hair-Wing Thorax Sulphur:

Hook: Standard Dry-fly
Tail: Cream Hackle Barbs tied in divided
Dubbing: Pale-Yellow and Sulphur-Orange Wapsi Superfine mixed. For a thorax-style fly the dubbing is applied all the way to the head of the fly.
Wing: Bleached Deer-Hair tied in a single clump and swept back
Hackle: Cream tied “thorax-style” (wound sparsely and widely-spaced from behind wing through thorax area and trimmed on the bottom).

Nicely Spotted Brown Caught on the Hair-Wing Sulphur Thorax

So was anything else hatching?
Actually – yes. There was also consistent caddis action all day that fish were responding to. Several caddis were part of this – one was about a size 16 with a drab gray/olive body and gray and black speckled wing. I never got a close up look at the other caddis but it was smaller – maybe a size 18 and it appeared to be a tan to light cinnamon wing color.

Caddis larvae were present in abundance – in addition to those pictured, there were also some that were basically the same, but more bright green.

Free-living Caddis Larvae

Light Cahills (Stenacron interpunctatum) also made an appearance. These were large – I’d say a size 12 verging on size-10. I didn’t get a picture, but the underside of the dun was pale-yellow and the wings were a transparent bright-yellow with black veins and speckles. These never hatched in great numbers but popped up through-out the day. Fish could be seen taking the duns.

Cahill Nymph

Cahill Nymph Underside

Gratuitous Trout Picture