Summer is moving quickly, way too quickly, with September just a few days away. The one overwhelming factor influencing fishing on the Bighorn River this year has been water temperature. It has dictated are seasonal insect hatches since spring and has brought us totally different hatch cycles this year compared to last.
Yesterday morning the water temp was 48 degrees in the side channels at the 3 mile boat ramp and 50 degrees at Mallard’s Access. Remember side channels are warmer right now than the main river. The main river at three mile could have been as low as 46. By early afternoon it was 51 degrees in the corrals about 3 to 4 miles below 3 mile. By late afternoon it was 55 or 56 degrees at Bighorn Access and about 58 down towards Two Leggins. The best temperature for mayfly hatches of PMD’s and tricos, that typically emerge this time of year is 52 -58. 52 at night and 56 – 58 during the afternoons.
As you can see current temperatures are not in that range and probably won’t get there this year at least on the upper 13 miles where 90% of anglers are fishing. This means that the hatches will trickle off during there seasonal emergence period and will most likely show up later than normal. Hatches will be heavier where the water is warmer.(Side Channels and farther down river)
With that said black caddis are out river wide. You will see them in fishable numbers but they are not yet boat covering hatches like “normal” years. Water temperatures still have time to warm up in early September and bring huge emergences of these bugs. One of the biggest keys to finding good dry fly fishing right now is being observant. Fish are up out there just in sneaky spots. Keep your eyes open.
Anglers are chomping at the bits to fish tricos right now because of how good they were last year. They are not presently out in fishable numbers where anglers are fishing. Think Mallard’s or Two Leggins fi you want to find a few of these tiny bugs hatching. Again this hatch lasted into November last year and there is plenty of time for them to get going on the upper river.
Mahoganies and Pmd’s are present right now from 3 mile to mallard’s access. We often DO NOT talk about the mahogany hatch because you typically never see the duns and the spinner fall only lasts for a day or two and often found only below Bighorn. With the unusually cold water, it has lasted longer this year for whatever reason. For the past two weeks anglers have been CRUSHING fish on the surface when these size 14 – 16 spinners are on the water. PMD’s can be found in isolated areas from 3 – B and still quite a few daily down to Mallard’s access.(Again water is warmer the farther you are from the dam)
Nymph fishing same old, it’s awesome. Grey or pink sowbug with a small baetis or midge in the morning. Afternoon – sowbug with a small pmd or black caddis pupa will get you into fish all day. Fish are in there typical feeding stations in the fast water riffles.
Categorised in: Fishing Reports
This post was written by Bighornangler