By Montana Grant

Posted: November 30, 2019

The famed Bighorn River trout fishery is in distress. The trout numbers are the lowest since surveyed, for the first time in 1992.

The trout fishery is literally being flushed away! High water discharges from the Yellowtail Dam are occurring at exactly the worst time for spawning to have a chance. Brown trout spawn in late Fall and early Winter. Rainbows spawn in the Spring. The eggs are protected in the rivers gravel beds until a huge runoff happens in March-April. Later in the Summer, the water releases increase even more. Annual trout eggs are flushed down the river along with important spawning gravels.

The 2017 and 2018 hatches were both a bust. Water releases were 7610-9070 cfs. during the time when the eggs were most vulnerable. Later in these Summers the flows increased to 10,000 cfs. Surviving fish are from the 2014 and 2016 hatches. They range in size from 8-15 inches I size. Back in the 19900’s, you rarely caught a trout under 18 inches. Because of this, the Bighorn became the supreme fly-fishing destination.

Currently, the highest trout population is found near the Yellowtail After bay dam. 370 Brown trout and 870 Rainbow trout per mile were surveyed. The numbers decline as you travel downstream.

Sadly, fishing pressure has remained high. During my last fishing visit, I caught only a few fish without hook scars or signs of distress common from overfishing. Like the Madison River, we are loving our Montana fisheries to death. Pressure from overfishing, and poor Catch and Release techniques, are only making the fishery worse.

Fishing reports sound positive and promising. The resorts and trout shops, rentals, and businesses need the crowds to spend their money in their community. Skilled anglers can catch fish, but the numbers and size are delated from the “Good Old Days”.

High water years, drought, flood control, irrigation demands, and down river water needs determine the amount of water released from the Yellowtail Dam.

Back in the 1980’s and 90’s, it was common to net several dozen trout a day during the prime hatches. The famous PMD hatch was simply amazing. Catching several fish up to 20 inches a day was routine, if you had decent fishing skills. The high waters have also flushed the insect life out of the river.

Currently, the Montana FWP, the Federal Bureau of Reclamation, the Yellowtail Dam Managers, and local protective organizations are working together to resolve these issues. Without stocking, the future will be dim for a few more years, if the flows are managed to benefit the trout fishery.

The Bighorn River needs a few years to recover. Keep this in mind when looking at the Madison River and other Blue-Ribbon trout waters in our crowded fisheries. Commercial demands are threatening our trout ecosystems.

Slack Lines!

Montana Grant

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