Anglers often wonder if there are big trout in the Firehole River. The answer is yes. But there aren’t many of them, at least compared to thirty years ago. The river is warmer now than it was then (for several reasons), which effectively speeds up the metabolism of the trout. Bottom line is that they grow very quickly, but the vast majority don’t live long enough to achieve a large size. The ones that do are invariably brown trout.
Intentionally finding and catching a big one requires extreme stealth, good eyesight, and the ability to cast accurately and delicately. Here’s a picture I took recently of a large brown in position. There were Pale Morning Dun mayflies hatching at the time and this fish was eating the nymphs, feeding exclusively beneath the surface (though not far beneath). I estimate him between 18 and 19 inches. A fine fish anywhere, and a trophy on the Firehole.
In seeking an even closer vantage point after taking this photograph, I alerted the fish to my presence. He drifted slowly downstream, taking shelter in a tangle of logs.