This summer has been warmer and drier than normal around southwest Montana, but so far stream temperatures have stayed below the level of concern on the Madison River outside of Yellowstone National Park.
“As long as we don’t get scorching hot days, we don’t expect to see water temperature problems at least to the point of causing fish mortalities in the river,” said Pat Clancey, Montana Fish, Wildlife and Parks fisheries biologist in Ennis.
Currently, water coming out of Hebgen Dam is averaging about 69 degrees, Clancey said. But that water is adjusting to the normal temperature fluctuation in the main Madison River. That means 10 to 15 degree swings in temperature each day.
“The water temperature is going to start adjusting as it proceeds down river,” he said.
The higher water temperatures out of Hebgen Lake are due to the work PPL is continuing to do at Hebgen Dam to fix the intake structure that was damaged in 2008.
When the dam is functioning normally, the water released into the Madison River comes out of the bottom of the reservoir. But during the construction work on the dam, the water is coming off the surface of the reservoir and down the spillway.
“We are seeing higher temps coming out of Hebgen then occur in a normal year,” Clancey said.
In response to summer water temperatures, trout may act a bit differently, he said. They may seek out cover and deeper holes over the course of the day. They may also be more active at certain times than they normally would.
Local fly fishing outfitter John Way, who owns The Tackle Shop in Ennis, is seeing good fishing both on the Madison and the Beaverhead Rivers.
In fact the Beaverhead River has been hot lately.
“We’ve been fishing micro mayfly nymphs and little hares ears and they’re just eating it up,” Way said.
On the Madison River, he’s seen a few hoppers, but his success has been mainly on smaller nymphs, like a serendipity or a three dollar dip. These he fishes behind a bigger nymph like a size 12 prince nymph.
The fish seem to have moved away from focusing on feeding near the banks and are found more around structures in the middle of the river, Way said.
In the near future, he looks for the hopper bite to turn on along with spruce moths on the upper river near Lyons Bridge.
Fishing restrictions are going to be in place starting Wednesday in Yellowstone National Park, according to a press release issued Monday by the National Park Service.
Fishing will be closed due to water temperatures in the Gibbon River below Gibbon Falls, Firehole River below Keppler Cascades and the Madison River. Water temperatures in the Gibbon River have been above 73 degrees for most of the past two weeks and above 78 degrees in the Firehole River.