Fishing the Flows
The Bighorn River is a tailwater fishery that is shaped by the water releases from the Yellowtail and Afterbay dams. Flows in the
Bighorn River during any given year can range from 2,000 cfs to 12,000+ cfs. The amount of water being released from the dam is important to Bighorn River fly fishers for several reasons. The flow of the river affects where trout will lie in the river, what insects they have to feed on and it sometimes dictates what techniques an angler can use to catch them. Below I will give a general overview of conditions at each flow stage and how each flow affects an anglers fishing.
2,000 – 4,500 cfs This is what most anglers consider our standard flows for the river. We typically see these flows from July – April. At this river flow the Bighorn is at its most enjoyable to fish. Anglers are able to both float and wade the river with ease and comfort. Also, every technique including dry flies, nymphs and streamers fish well during this flow stage. The fish utilize the entire river channel to hold and anglers are able to present a fly just about anywhere successfully.
4,500 -7,500 cfs At these river flows the river is typically in transition and either on the way up or down as runoff is occurring. We typically see flows in this range during May, June and early July. During this flow stage nymph fishing is typically the most productive for anglers, but dry flies are not out of the question. The one thing we typically don’t like to see is large, quick jumps in the water during this time. Small calculated bumps if you will, are best for the fishing. The river at this flow stage is still wadeable, becoming more challenging as we reach the 7,000 cfs mark. You can wade around islands, in side channels or well defined inside bends. The fishing is still very good at this time.
7,500 – 12,000 cfs This last flow stage is about the largest flows we see on the river and occur during high water years. These flows typically occur in June. At this point nymph fishing from the boat is your best and just about only option. Wade fishing for the most part is out of the question and inexperienced rowers may want to think twice about launching a boat. While flows are huge at this time, the fishing will remain consistent with long leaders, extra weight and double nymph rigs. Another factor at this time is that once the water releases go over 7,500 cfs, water begins to be release over the top of the dam rather than the bottom. This brings the water temperature up in the river, which does two things: It jump starts our summer hatches of PMD’s and Yellow Sallies, which typically hatch when the water is in the mid 50’s and the raised water temp’s triggers the growth of aquatic vegetation in the river.
Yellowtail Dam is what creates the amazing fishery that is the Bighorn River, regardless of flow levels anglers can enjoy plenty of success on the river. Embrace the challenges and fishing conditions that are associated with each flow stage, and match your angling techniques accordingly.
This post was written by Bighornangler